IMSRPVII 022.209773 IL6msr no. 9 (JpW>^ SUBSIDENCE INVESTIGATIONS OVER A HIGH-EXTRACTION RETREAT MINE IN WILLIAMSON COUNTY, ILLINOIS: FINAL REPORT B. B. Mehnert, D. J. Van Roosendaal, R. A. Bauer, D. Barkley, and E. Gefell y linois Mine Subsidence Research Program 1994 iMSRpytf iX cooperating agencies ILLINOIS STATE GEOLOGICAL SURVEY Illinois Department of Energy and Natural Resources BUREAU OF MINES United States Department of the Interior *<*& ***\^ v &o v ILLINOIS STATE GEOLOGICAL SURVEY 3 3051 00005 6212 LIBRARY. SUBSIDENCE INVESTIGATIONS OVER A HIGH-EXTRACTION RETREAT MINE IN WILLIAMSON COUNTY, ILLINOIS: FINAL REPORT B. B. Mehnert, D. J. Van Roosendaal, R. A. Bauer, D. Barkley, and E. Gefell Illinois Mine Subsidence Research Program ^ 30 A9® W 00^ sv>* M# 1994 IMSRP \W [ h ILLINOIS STATE GEOLOGICAL SURVEY Morris W. Leighton, Chief Natural Resources Building 615 East Peabody Drive Champaign, IL 61820-6964 The Illinois Mine Subsidence Research Program (IMSRP) was estab- lished in 1985 to investigate methods and develop guidelines for under- ground mining operations that aim to maximize coal extraction yet pre- serve the productivity of prime farmland. The research program was initiated by the Illinois Coal Association and the Illinois Farm Bureau. The Illinois State Geological Survey, a division of the Illinois Department of Energy and Natural Resources, directed the IMSRP. Participating research institutions included Southern Illinois University at Carbondale, the University of Illinois at Urbana-Champaign, Northern Illinois Univer- sity, and the Illinois State Geological Survey. A 5-year Memorandum of Agreement, signed by the State of Illinois and the Bureau of Mines, U. S. Department of the Interior, ensured collaboration, cooperation, and financial support through 1 991 . Major funding was also provided by the Illinois Coal Development Board. This publication is one in a series printed and distributed by the Illinois State Geological Survey as a service to the IMSRP. Printed by authority of the State of Illinois/1994/800 CONTENTS ABSTRACT INTRODUCTION Scope and Purpose Background and Previous Studies Natural resources affected by mine subsidence Methods of mining Overburden fracturing Hydrogeologic effects 2 Surface subsidence characteristics 2 Physical Setting 3 Site selection 3 Physiography 3 Surficial geology 5 Bedrock stratigraphy and structure 5 Hydrogeology 5 Mine Description 7 GEOTECHNICAL MONITORING PROGRAM 7 Introduction 7 Instrument layout 7 Mine operations 8 Surface Subsidence and Deformation Monitoring 8 Surveying 8 Tiltplates 10 Overburden Characterization 11 Exploratory drilling 11 Laboratory testing for intact rock properties 1 1 Overburden Deformation Monitoring 12 Multiple-position borehole extensometer 12 Time-domain reflectometry 13 Hydrogeologic Investigations 14 Drift piezometers 14 Bedrock observation wells 1 4 MONITORING PROGRAM RESULTS 17 East Cluster 18 Surveying and subsidence characteristics 18 Overburden deformation monitoring 19 Hydrogeologic investigations 21 West Cluster 24 Surveying and subsidence characteristics 24 Hydrogeologic investigations 25 CONCLUSIONS 25 RECOMMENDATIONS 27 ACKNOWLEDGMENTS 27 REFERENCES 28 APPENDIXES A Overburden Characterization 32 Rock Mechanics Laboratory Results 32 Geotechnical Core Log 33 B MPBX Readings and Calculations for Both Clusters 47 East Cluster MPBX Readings and Calculations 47 West Cluster MPBX Readings and Calculations 50 C Surveying Data 51 Survey Coordinates for East Cluster Instruments and Monuments 51 Survey Coordinates for West Cluster Instruments and Monuments 54 D Elevation Changes due to Subsidence 57 Elevation Changes of East Cluster Instruments 57 Elevation Changes of West Cluster Instruments 60 E Water Level Readings and Precipitation Data 63 Piezometer Water Level Readings, East Cluster 63 Piezometer Water Level Readings, West Cluster 65 Precipitation Data from Marion Station 67 FIGURES 1 Two high-extraction techniques commonly used to remove coal 2 2 Approximate location of site in Williamson County, Illinois 3 3 Generalized stratigraphic column of the Carbondale and Modesto Formations 4 4 The Cottage Grove and other major fault systems of southern Illinois 6 5 Partial mine map showing the monitored panel and adjacent workings 7 6 Instrumentation layout superimposed over the mine panel 8 7 Schematic map of east cluster instrument location and surface crack location 9 8 Schematic map of west cluster instrument location 9 9 Frost-free monument and rebar monument design 10 10 General tiltplate installation 11 11 Multiple-position borehole extensometer installation 13 12 Schematic of original TDR installation 15 13 Schematic of TDR installation with revised cable anchor 16 14 Schematic of piezometer and observation well installation 17 1 5 Subsidence profile characteristics of a longitudinal line for the east cluster area 1 8 16 Vertical drop of each MPBX anchor for the east cluster 19 17 Amount of strain measured between MPBX anchors 20 18 Deformation history of TDR cable at the east cluster 21 1 9 Photo of the east cluster TDR cable 22 20 Piezometric response of the drift piezometers (east cluster) 23 21 Piezometric response of the bedrock piezometers (east cluster) 24 22 Piezometric response of the drift piezometers (west cluster) 25 23 Piezometric response of the bedrock observation wells (west cluster) 26 TABLES 1 Summary of overburden unit thickness and thickness ranges 6 2 Summary of subsurface overburden movements in the east cluster 22 ABSTRACT The effects of high-extraction retreat (HER) mining on the overburden were investigated using two instrument clusters placed over one HER panel in Williamson County, Illinois. The amount, extent, and location of fracturing in the bedrock were measured, and the effects of the fracturing on the local hydrogeology were examined. Instruments used included surface monuments, piezom- eters, extensometers, and two time-domain reflectometry cables. The Illinois State Geological Survey (ISGS) monitored the panel before, during, and after subsidence. This was the first time such infor- mation was collected over an HER operation in Illinois. This site is one of three investigated under the Illinois Mine Subsidence Research Program to study the effects of mining on the overburden. INTRODUCTION Scope and Purpose High-extraction mining techniques are being used more frequently in Illinois to maximize coal- mining productivity and to decrease the cost of the delivered product. Underground coal extraction by these techniques causes immediate collapse of the overburden and subsidence of the ground surface. Farmland and water resources may be affected by surface subsidence. The Illinois Mine Subsidence Research Program (IMSRP) was created to address these concerns. This study is one of several projects performed under the IMSRP with funding from the U.S. Bureau of Mines, Illinois Department of Energy and Natural Resources Coal Development Board, and the Office of Surface Mining. The purpose of this investigation was to study the effects of high-extraction retreat (HER) mining on the overburden. Two instrument clusters were installed over an HER panel to investigate the following: subsidence of the ground surface; amount, extent, and location of fracturing in the bed- rock overburden; and hydrogeologic changes caused by bedrock deformations. Surface monuments, piezometers, extensometers, and two time-domain reflectometry cables were used to monitor overburden and ground surface response. The Illinois State Geological Survey (ISGS) monitored the panel before, during, and after subsidence. This was the first time such information was collected over an HER operation in Illinois. This report summarizes the geotechnical monitoring program and the results of monitoring through- out a 3-year period. Unfortunately, the mining company did not complete the panel and only one- half of the instrumentation was undermined. The undermined instruments were located near the start of the panel. Background and Previous Studies Natural resources affected by mine subsidence Illinois is the second largest producer of agri- cultural commodities and the fifth largest producer of coal in the United States. Problems some- times occur in ensuring that both the farmland and the coal resources are used to their maximum potential. Subsidence-induced ground movements modify surface drainage, which may affect crop yields of the gently rolling farmland. Clearly, coal and farmland are valuable resources and impor- tant to the state's economy. Mine operators are required to manage the impacts of underground mining on near-surface hydrology and surface-drainage patterns. Methods of mining Two high-extraction mining methods, HER and longwall, are used in Illinois; each produces immediate, planned subsidence. Figure 1 shows the configuration of the two high- extraction mining methods commonly used. These two methods differ in the amount of fracturing and hydrologic changes caused in the overburden and the amount of damage produced in surface structures. High-extraction retreat methods are similar to room and pillar mining techniques except that pillars are removed on retreat. In this type of operation, small sections of the panel collapse and subside as they are extracted. The roof may stay up until several hundred feet have been mined out and then collapse. In contrast, the longwall method removes all the coal across a wide working face, which is temporarily supported by hydraulic shields. A double row of pillars separates the panels. The entryways of the pillars are used for ventilation and transportation. As the mine face advances, the overburden behind the shields is left unsupported and collapses into the void. Surface subsi- dence immediately follows this collapse. Overburden fracturing Coe and Stowe (1984), Ming-Gao (1982), and Whitworth (1982) investi- gated the location and amount of fracturing in subsided bedrock over longwall operations in Ohio ■ ■ I ■ high-extraction retreat longwall Figure 1 Two high-extraction techniques commonly used to remove coal. Both result in controlled surface subsidence. (USA), Jiangsu Province (China), and South Staffordshire Coalfield (United Kingdom), respectively. Before the IMSRP efforts, Conroy (1980) performed the only study concerning fracturing above a high-extraction mining operation in Illinois. He grouted two time-domain reflectometry (TDR) cables into boreholes that extended from the ground surface into a 625-foot-deep longwall mine. Conroy found that the bedrock movements severed one of the cables within 100 to 150 feet of the surface. Hydrogeologic effects Fracturing of the overburden may affect water-bearing formations by creating voids and increasing secondary permeability as found in the Appalachian Plateau of Pennsylvania (Booth 1986). In a study in England, Garritty (1982) suggested that fracturing of the bedrock up to the surface may hydrologically connect an aquifer or surface water body with the mine. While studying a mine roof in Illinois, Cartwright and Hunt (1978) observed localized, open, vertical joints that had been caused by faulting; they speculated that these joints could pro- vide a direct passage for water from higher strata in the immediate roof. These fractures were dis- continuous, however, and did not provide any hydrologic connection to the surface. In another study in Illinois, Nieto (1979) found that mines with faults showed no leakage, even though they were located about 600 feet under the Rend Lake reservoir. Similarly, subsequent studies in Illinois (Brutcheret al. 1990, Van Roosendaal et al. 1990, Booth and Spande 1990) have shown that dis- continuous, localized fracturing caused by strains in the bedrock may occur without any hydrologic connections to the surface. Before this study was initiated, the hydrogeologic effects of subsidence were investigated by several researchers (Coe and Stowe 1984, Duigon and Smigaj 1985, Garritty 1982, Owili-Eger 1983, Pennington et al. 1984, Sloan and Warner 1984). In studies of the Appalachian Plateau by Coe and Stowe (1984), Booth (1986), and Pennington et al. (1984), drops in water level were observed in wells that were undermined using the longwall method. Water levels partially or completely recov- ered, however, several months after being undermined by the longwall method (Owili-Eger 1 983). Subsequent studies in Illinois by Pauvlik and Esling (1987), Brutcher et al. (1990), and Booth and Spande (1 991 ) have also documented similar observations. Booth and Spande (1 991 ) also deter- mined that aquifer characteristics of an originally poor aquifer actually improved after mining. Surface subsidence characteristics Planned subsidence is produced by both the HER and long- wall methods of mining. Two types of surface subsidence profiles, static and dynamic, are produced during high-extraction mining (Kratzsch 1983). The static profile reflects the final changes in elevation after subsidence. Static profiles are generally measured transverse to the panel to show the final shape Alexander Pulaski ffl Site Location Figure 2 Approximate location of site in Williamson County, Illinois. of the subsidence trough. Dynamic profiles are documented as surface subsidence occurs. For instance, longitudinal survey lines are used to document the dynamic traveling subsidence wave that develops on the ground surface behind the advancing mine face. Near the sides of the panels, the progression from dynamic to static subsidence is complex (Van Roosendaal et al. 1 991 ). Strain and slope characteristics of the two different profiles are unique and depend on the over- burden properties and the rate of mining. Kratzsch (1983) states that a fast rate of advance in visco- elastic strata produces a flatter dynamic profile; strain and slope values are greatly reduced, as compared with those of the static profile. If the strata are fractured and loose, however, the dynamic pro- file becomes much more severe as mining-advance rates increase. Physical Setting Site selection Several factors were considered during the site selection process. First, an HER mine had to be available for study within a reasonable time frame. It was essential that instruments be installed well before the site was undermined so that site characterization and base-line data col- lection could take place. Next, the full cooperation of the mine operators and surface owners was required. Formal agreements with these parties were negotiated prior to initiation of work. Finally, the site had to be accessible and well suited for both instrument installation and long-term monitoring. The above criteria were used to select an HER panel in northeastern Williamson County, Illinois. Fig- ure 2 shows the approximate location of the mine panel about 2 miles east-southeast of the town of Pittsburg in the southwest quarter of Section 6, T9S, R4E, of the 3rd Principal Meridian (Pittsburg Quadrangle). Physiography The study site is located in the Mount Vernon Hill Country physiographic division of Illinois (Leighton et al. 1948). The geomorphology of the area is characteristic of a maturely dissected, sandstone-shale plain of low relief mantled by thin (<40 feet) lllinoian drift. Restricted uplands and broad alluviated valleys occur along the larger streams. Surface topography above the panel is gently rolling. The maximum relief is about 40 feet. Surface elevations range from about 480 to about 520 feet above mean sea level (msl) and slopes vary from less than 3% to more than 18%. The topography in the area is primarily bedrock controlled (Horberg 1950). Bedrock features are modified, however, by glacial action and somewhat subdued by a thin mantle of deeply eroded drift that covers the region (Leighton et al. 1 948). «> / / / CO 111 Q_ LU Z LU o p CO LU _l 0_ CO LU CO LU Q ■D O CO T3 C o -O 1000 ft (305 m), ticks on down thrown side fault < 1000 ft (305 m). ticks on down thrown side monocline syndine (•) Williamson County site location Figure 4 The Cottage Grove and other major fault systems of southern Illinois (after Nelson and Krausse 1 981 ). Groundwater is pumped from large diameter (2-5 feet) dug wells, which provide water for private and domestic purposes. These wells penetrate sand and gravel lenses that are in the glacial drift and usually directly overlie the bedrock surface at depths of as much as 60 feet (Pryor 1953). These lenses are as much as 12 feet thick. Sasman (1953) reported static water levels in the dug wells from about 5 to 35 feet below the surface and at pumping rates that varied from about 5 to 15 gallons per minute. This information concurs with water well data obtained from the ISGS and the Illinois State Water Survey (ISWS). Smaller diameter wells have also obtained groundwater from the glacial drift; however, yields were much lower than they were from the dug wells. «d EC< 3, ■a. \e s . 2 ^ ^" 3 East Cluster (EC) West Cluster (WC) room-and-pillar f mininq N HER mining 400 800 ft Figure 5 Partial mine map showing the monitored panel and adjacent workings. Bedrock aquifers of the Pennsylvanian System in the study area are limited primarily to sandstone units; however, some fractured limestone aquifers were also reported (Pryor 1953). Static water levels in these wells ranged from about 10 feet to as much as 80 feet below ground surface. Mine Description The study site was situated over Panel 23 East of the Orient No. 4 Mine, which is operated by the Freeman United Coal Mining Company. Figure 5 shows the location of 23 East and adjacent work- ings. Mine plans called for a panel that is 2,300 feet long and 210 feet wide and has a seam 250 feet deep. The panel width was increased to 385 feet and the south edge of the panel was relo- cated northward during mining because of roof conditions. The operations at the mine were sus- pended on May 1 8, 1 987, after the panel had progressed only 900 feet. Only the east cluster of instrumentation was undermined by the HER method. The west cluster was undermined by the room-and-pillar method only, but it is adjacent to the solid, unmined portion of the panel. GEOTECHNICAL MONITORING PROGRAM Introduction The instrumentation for this study was selected to measure the geotechnical and hydrological effects of subsidence on the overburden. Engineers International (El) of Westmont, Illinois, proposed an instru- mentation plan that was reviewed and accepted by the U.S. Bureau of Mines, Twin Cities Research Center (USBM), and the ISGS. Representatives of the USBM let the contract to Engineers International to implement the instrumentation program and to conduct base-line surveys. Engineers International was responsible for installing most of the instruments including four bedrock and 1 1 drift piezometers, two multiple-position borehole extensometers (MPBXs), and 30 surface monuments (El 1988). The ISGS, with assistance from Northwestern University, installed two time-domain reflectometry (TDR) cables, five tiltplates, four control monuments, survey turning points, and 14 additional rebar monu- ments to determine the static subsidence profile transverse to the panel. The drilling program was conducted by the Soil and Rock Drilling Corporation of Bartlett, Illinois, under separate contracts. Engineers International installed the instruments in June 1986. The ISGS installed the tiltplates and additional survey monuments in March 1987. Instrument layout Wyant Surveying Company of West Frankfort, Illinois, used mine coodinates to stake out the panel center line on the surface. The instrumentation layout shown in figure 6 was designed to measure two different responses of the overburden to mining of the panel by placing one instrument cluster near the beginning of the panel (east cluster) and one near the -# — genera m ning direction ^ J_ i west cluster survey "^*^«^^ monument ^ line „..„«, 4 ► : f east cluster 1 m survey 1 t monument line 8 1] rebar monument line 1 1 1 V J 1 / / room-and-pillar mining HER mining ^ TDR 200 ft Figure 6 Instrumentation layout superimposed over the mine panel. center (west cluster). The initial subsidence at the beginning of a high-extraction panel is usually sudden and extensive because the roof stays up until a critical span has been undermined. The subsequent subsidence that takes place shortly after roof support has been removed causes a dynamic subsidence wave behind the retreating face. The instrumentation in the west cluster was to monitor the effects of the dynamic subsidence wave. Each instrument cluster consisted of a TDR cable, MPBX, one shallow (100 feet) bedrock obser- vation well, and one deep (160-203 feet) bedrock observation well (figs. 7, 8). A line of surface monuments and drift piezometers extended from each instrument cluster; each line was oriented nearly east to west, perpendicular to the anticipated front of the subsidence wave. The west instrument cluster included additional rebar monuments, which were installed perpendicular to the panel center line to record the static profile over the edge of the panel. Additionally, five tiltplates were adjacent to successive east-west monuments. Two surface control monuments and two drift piezometers were placed well away (500 feet) from any undermined areas for both east and west clusters. Mine operations Development and mining of Panel 23 East began in early 1 987. Before mining, the company changed the panel dimensions, which placed the instrument clusters closer to the south side of the panel than was originally planned. The mine was abruptly closed shortly after pillar extrac- tion had begun and before the face had reached the west instrument cluster. A company press release stated, 'The mine company suspended operations due to economic conditions effective 12:01 a.m., Monday, May 18th, 1987." Although the mine company hoped to resume operations as soon as market conditions permitted, operations were not continued. Surface Subsidence and Deformation Monitoring Surveying Monument design and installation Two types of surface monuments were installed at the site. Frost-isolated monuments were anchored below the frost zone (fig. 9). The section of pipe that extended to the surface was surrounded by PVC pipe to isolate it from soil movements. Control monuments and long-term monitoring points were constructed in this manner. Simple rebar monuments, as shown in figure 9, were also used. Rebar monuments 3 feet in length were driven 2.5 feet into the ground as temporary monuments and turning points. The locations of surface monu- ments were selected on the basis of the mine layout. They were spaced 20 to 25 feet apart. Sun/eying methods and frequency The ISGS began base-line monitoring in September 1986. Several level surveys were made with a WILD NA-2 as a check on the preliminary data received from Engineers International. A Lietz SET3 total station equipped with a SDR2 electronic notebook TDRv^ qow MHMM^MMMNMMM M15M17 M18 M19 P2E room-and-pillar mining HER mining piezometer in drift # survey monument 100 ft t Figure 7 Schematic map of the east cluster instrument location and surface crack location. room-and-pillar ♦ rebar monument mining o piezometer in drift HER mining survey monument 100 ft I Figure 8 Schematic map of the west cluster instrument location. ground surface 6-in. dia PVC pipe 5-in. dia. PVC duct 30 in. cement grout 2-in. dia. steel pipe ^^ 36 in. 36 in. varies 1 in. rebar rebar monument 24 in. I 6 in. I frost-isolated monument Figure 9 Frost-isolated monument and rebar monument design. was used to set new control monuments for each instrument cluster. The west cluster instrument base line was set from ISGS control monuments during the period of April 2-30,1987. Information provided by mine personnel was used to track the mining progress and to determine the frequency of monitoring. Monitoring surveys to document time-related effects were most fre- quent during the early, most active stage of subsidence. The east cluster survey monuments were monitored frequently for the first 8 days following the initial roof failure and steadily thereafter through the end of May 1987. The frequency of monitoring decreased with the rate of movement. Instruments were monitored about every 3 months through January 1988. Long-term monitoring continued to document residual movement of the overburden through December 1989. The west cluster was not undermined by the HER method, although it was partially undermined by the room-and-pillar method. Monitoring of the west cluster survey monuments was performed to determine whether any changes were due to the approaching mine face. Tiltplates Tiltplates installed in the west cluster were to be used to record changes in slope as the subsidence wave passed. Tiltplate installation is illustrated in figure 10. The plates were set into mortar beneath the frost zone (12-15 in.) and inside of 6-inch PVC casings with caps. The tilt- plates were placed next to five frost-isolated monuments in the west cluster only. Unfortunately, the area did not subside. 10 PVCcap tiltplate (5.5 in. dia.) cement grout Figure 10 General tiltplate installation. Overburden Characterization Exploratory drilling A hole was drilled at a 10.5° angle from vertical, with a dip direction of S18.5°E near the center of the panel (west cluster). The coring was performed off-vertical so as to encounter any vertical joints in the formations. Core description, core recovery, fractures, and rock quality designation (RQD) were logged in the field by Engineers International. A stratigraphic section developed on the basis of the resulting depth-adjusted core log is presented in figure 3. The bedrock here is composed of Pennsylvanian-age siltstones and shales with approximately 49 feet of glacial deposits overlying it. The bedrock overburden is composed of approximately 54% shales, 11% siltstones, 23% sandstones, and 6% limestones; coals and claystones make up the remaining 6%. The geotechnical core log is presented in appendix A. The GeoTechnical Graphics System software (1991) was used to combine all the field logging notes into a present- able and legible core log. Rock quality designation Rock quality designation (RQD) is a standard parameter for evaluating the degree of fracturing of a rock core. Rock quality designation is used as an index property to indicate rock-mass quality. The RQD value, expressed as a percent, is the quotient of the sum of the length of all core segments longer than 4 inches divided by the length of the core run. Frac- tures caused by drilling or handling are not included in the determination. Fracture frequency Total fracture frequency per core run, in units of fractures per foot, is deter- mined by counting the number of natural fractures per core run and dividing by the length of the core run. All natural discontinuities are counted, including fractures along weak bedding planes and joints. As with RQD, breaks caused by drilling and handling are not included in the determination. Laboratory testing for intact rock properties Rock characterization was performed in the ISGS laboratory. Core samples were tested for unconfined compressive strength, modulus of elasticity, indirect tensile strength, specific gravity, shore hardness, and point-load index. The standards and suggested methods of the American Standard and Testing Materials (1988) and International Society for Rock Mechanics (1985) were followed. Results of all tests performed on the rock core are given in appendix A. Unconfined strength and elastic modulus Samples were cut with a saw to near the allowable toler- ance before they were lapped. Additional preparation of the sample consisted of lapping to a height-to-diameter ratio of 2 to 2.5 with a tolerance for nonparailelism of 0.001 inch (according to ASTM D 4543-85 1988). The 2:1 height-to-diameter ratio requirement was not always main- tained, especially within a section of core that was quite fractured. Sample loading was under constant strain conditions, as allowed by ASTM D 2938-86 (1988). As recommended in Brown (1 981 ), the sample ends were not capped. The elastic modulus was obtained directly from the plot of "load versus deformation." The elastic modulus represents the slope of the line tangent to the elastic portion of the stress/strain graph 11 and at 50% of the ultimate compressive strength. The ultimate compressive strength was found by dividing the ultimate axial force by the area of core perpendicular to its axis, as suggested by the ISRM. Indirect tensile strength Discs 1 inch thick were compressed diametrically between high modu- lus (steel) platens. The values of indirect tensile strength, ot , were calculated by the following equation (Brown 1981): IP °' = ^ where P = axial load (lbs) D = diameter (in.) f = thickness (in.) Axial point-load index The method suggested for the axial point-load index by the ISRM Com- mission on Testing Methods (1985) was used. Samples with a height-to-diameter ratio of 0.3 to 1 .0 were tested. The samples were placed between two spherically truncated, conical platens of the standard geometry (60° cone). The load was steadily increased such that failure occurred within 10 to 60 seconds, and the failure load, P, was recorded. The point-load index was calcu- lated using the following equation suggested by Broch and Franklin (1972): where / s = uncorrected point-load strength P = axial load (lbs) t = thickness This equation does not take into account varying sample thicknesses, therefore a size correction is required. The size correction for the axial point-load index T500 of a rock specimen or sample is defined as the value that would have been measured by a diametral test with D = 50 mm (Brook 1980). The corrected axial point-load index is calculated by the following equation: 7-500 = 211.47-^ where T 500 = corrected point-load index (MPa) P = load (kN) A = diameter x thickness (mm 2 ) Moisture content A center portion of each of the samples tested for unconfined strength was used for moisture content determination. Moisture content was calculated as a percentage of the dry weight of the sample as specified in ASTM D 2216-80 (1988). Specific gravity The specific gravity of all samples was determined in accordance with ASTM D- 1 188-83 (1988). Samples were oven dried and coated with a polyurethane spray. The specific gravity for each sample was obtained by comparing its weight submerged in water to that in air. Shore hardness A model D schleroscope, manufactured by Shore Instrument and Manufactur- ing Company, was used for hardness determination of compressive strength specimens. Each of the values in the summary tables is an average of the highest ten tests from a total of 20 tests performed on the lapped ends of the uniaxial compressive strength test specimen as described in Brown (1981). Overburden Deformation Monitoring Multiple-position borehole extensometer Two 6-anchor, multiple-position borehole exten- someters (MPBXs) were installed at the site, as shown in figure 1 1 . The anchors of each MPBX were grouted at depths of 50, 75, 100, 125, 150, and 175 feet below the ground surface. The exten- someters mechanically monitor vertical overburden movements at each level. Anchor displace- ments are transmitted by the fiberglass rods to the surface, where movement of the rod tips is 12 .reference head cover - guide plate- ground surface micrometer measurements made between ends of rods and reference head yA=VV\=VA :\\\=\\\ \ -3-in. dia. (NX) boring expansive grout - anchor (1 ft lengh reinforcing bar) 3/8-in. dia. fiberglass rod with flush joints plastic tubing filled with oil coupling anchor NOTE: only two anchors shown for clarity Figure 11 Multiple-position borehole extensometer installation. measured relative to a reference plate. Displacements of the anchors relative to each other and to the reference plate indicate the magnitude and general depth interval of the vertical component of ground movements. Elevation control was maintained on the reference plates to establish absolute anchor movements. Appendix B contains the data collected for both the east and west cluster MPBX. Time-domain reflectometry The time-domain reflectometry (TDR) technique was used to docu- ment fracture development caused by subsidence in the overburden. This technique was developed by the power and communications industries to locate breaks in transmission cables. A TDR tester sends ultra-fast rise time voltage pulses down the coaxial cable. Deformations in the cable reflect signals back to the tester. Reflections appear as a distinct signature versus distance on a cathode-ray tube (CRT) or strip-chart recorder. The cable is crimped every 20 feet to produce recogniz- able signals at known intervals on the cable, which increases the accuracy of distance measurements. 13 Researchers at Northwestern University (Dowding et al. 1988, 1989), determined the optimum ca- ble size, bonding strength, and grout composition; they also characterized the signatures caused by different modes of deformation (e.g., tension versus shear). A generalized TDR installation is shown in figure 12. One 0.5-inch-diameter unjacketed coaxial cable (Cablewave FXA 12-50) was installed at each instrument cluster. In the west cluster, a cable that was 269 feet long and extended through the Herrin Coal was grouted into the inclined bore- hole. The east cluster cable (256 feet long) was installed in a vertical borehole that did not pene- trate the coal. The TDR cable in the east cluster was designed with a weight or anchor of the type shown in fig- ure 12. This anchor design works best with a braided cable and not the solid outer conductor type used on this project because the outer conductor splits when the cable is bent around the bolt. Therefore, a new design was implemented for the second cable in the west cluster. The new design consisted of placing the TDR cable through a 5-foot-long piece of black pipe with a cable clamp placed over the cable below the pipe, as shown in figure 13. Electrician's tape was wrapped around the clamp to smooth its profile and prevent snags during cable installation. The entire cable was laid out on the ground and reference crimps were placed at intervals of 20 feet. Without reference crimps along the cable, location accuracy is on the order of 2% of the dis- tance from the tester to the cable defect. Crimps at known distances allow for much more accu- rate defect locations. The reflected signal is attenuated as a function of distance along the cable. Therefore, a wider crimp, consisting of adjacent, individual plier crimps, is required at greater depths to produce the desired signal amplitude of 40 mp. The grout had a 65% water-to-cement ratio by weight (7.6 gal/94 lb sack cement). High early strength Type III cement and 2% Intrusion- Aid (Intrusion-Prepakt, Inc.) were used, as recommended by Dowding et al. (1989). The grout was placed in the borehole up to the ground surface through the glacial material. The TDR instal- lation and monitoring was part of an ongoing contract with the Office of Surface Mining to test the application of using TDR to monitor overburden fractures. Results of several studies using the TDR technique over both active and abandoned mines may be found in Bauer et al. (1 991 ). Hydrogeologic Investigations The groundwater response to subsidence was monitored using two types of wells. Piezometers with 2-foot screens were used to document water levels in the drift material; the bedrock material was monitored using 20-foot screens in what is called here an observation well. Water level changes in the piezometers and observation wells reflect fluctuations in the piezometric head at the various screen depths. Drift piezometers A total of 1 1 piezometers were installed. Five were placed in or near each in- strumentation cluster, and one was located outside the area of anticipated subsidence. Alternat- ing shallow and deep piezometers were installed in the drift to record the effect of the subsidence on piezometric levels in the unlithified glacial materials. The general design for both bedrock and drift piezometers is shown in figure 14. Screen depths ranged from about 15 to 50 feet, and the screen interval was 2 feet. The deep drift piezometers were set near the bedrock surface. Design specifications called for 2.5 feet of 1 .0-inch screened PVC tubing surrounded by rounded river sand to a height of 5 feet above the screen. The sand was capped with a bentonite seal 2 feet thick, and the remaining borehole length was backfilled with a cement-bentonite grout. Small 1/2- inch riser tubing was used to reduce the response time to piezometric fluctuations. Piezometers were developed by pumping out all the fines before monitoring. Bedrock observation wells Design specifications for the bedrock observation wells were identical to those for the drift piezometers except that the screened section was 20 feet long in order to increase the infiltration area. One shallow observation well and one deep observation well were installed in each instrument cluster. Screen depths of both east and west cluster shallow observation wells were from 80 to about 100 feet below the surface in a low hydraulic conductivity unit. The screen depth of the west cluster deep observation well was from 183 to 203 feet in the Anvil Rock Sand- stone. The east cluster deep observation well screen was from 145 to 165 feet below the surface. 14 battery operated TDR cable tester BNC connector locking protective cover coaxial cable expansive cement grout chart record cnmp in cable (every 20 ft) STD bell reducer cable anchor Figure 12 Schematic of original TDR installation. 15 CRT screen battery operated TDR cable tester BNC connector locking protective cover chart record coaxial cable expansive cement grout pipe cable clamp cable anchor Figure 13 Schematic of TDR installation with revised cable anchor. 16 6ft vanes ffi^ varies 2ft 5ft screen interval: 2.5 ft for drift 20 ft for bedrock 2ft locking steel cap vented PVC cap ground surface mrnr~^r ■ 5-in. dia. steel casing cement grout 3/4-in. dia. PVC schedule 40 casing bentonite seal sand pack, gradation for concrete sand as per ASTM-C33 1-in. dia. slotted PVC well screen PVC plug Figure 14 Schematic of piezometer and observation well installation. MONITORING PROGRAM RESULTS In September 1986, instrument monitoring commenced, excluding the TDR cables that were first read on June 20, 1986, by ISGS and Northwestern University research teams. Engineers Interna- tional was responsible for collecting three sets of readings on all the instruments except the TDR ca- bles, tiltplates, and rebar monuments. Wyant Surveying Company conducted the surveys and set vertical and horizontal controls on the instrumentation. The data were reduced and a draft base-line report was distributed by Engineers International in February 1987. 17 c 10 20 - 30 40 - 50 - 60 M28 maximum tension M16 -0.3 dist. from rib/mine depth 0.5 Figure 15 Subsidence profile characteristics of a longitudinal line for the east cluster area. Survey coordinates and elevations for both the east and west cluster instrumentation may be found in appendix C. The east cluster instrument readings from March 26-27, 1987, changed dramatically from those taken just 2 days earlier. These changes reflected the effects of subsidence on the overburden of what was probably an abrupt initial failure of the mine roof at the beginning of the panel. At the west cluster, the MPBX, TDR, and tiltplates were unaffected by the mining. Some subsi- dence was detected, however, and piezometric changes were observed in the bedrock well. All the instruments were last monitored on September 25, 1987, after which only the drift and bedrock piezometers were read. Long-term monitoring of the west cluster instruments continued through October 1988. East cluster instruments were monitored through December 1989 to document water level recovery and any residual movement of the surface and overburden. East Cluster Surveying and subsidence characteristics Surface movements of the east cluster instrumen- tation were measured with a Lietz SET3 total station and recorded by an SDR2 electronic notebook. Subsidence was first detected at the east instrument cluster on March 26, 1 987. Coordinates obtained for the monument points on March 26 did not match those of previous surveys, including one taken 2 days earlier. Also the grout apron around the MPBX was broken, and the casing appar- ently dropped about 0.4 foot relative to the ground surface. Subsequent readings of the MPBX, TDR cable, monuments, and drift and bedrock piezometers all registered changes, confirming the subsidence event. The maximum elevation change determined by ISGS personnel was a drop of 3.16 feet at the MPBX as of January 12, 1988. The ground surface dropped approximately 2.7 feet at the MPBX, about 0.46 foot less than the casing, which was apparently pulled down into the disturbed drift by the anchor rod tubes. About 95% (on average) of the recorded subsidence occurred in the first 10 weeks following undermining. Appendix D contains the elevation changes for the east cluster instrumentation. A surface crack up to 0.3 foot wide, located at the point of maximum tension, stretched in an arc from the east end of the panel westward through the east instrument cluster and beyond, roughly paralleling the edge of the mined-out area or panel rib (fig. 7). The crack was traced from a graben- like feature perpendicular to the center line at the east end of the panel. The crack opened to a maximum width of about 1 foot by April 16, 1987, when the pillaring sequence had advanced approxi- mately 200 feet. Although data were collected from the east cluster instrumentation, some subsidence characteristics could not be accurately determined because of the geometry of the instrumentation layout relative to 18 a> o c O -O CD 480 470- 460 450 initial subsidence -r y plugged/dry ■MM -» ■ ■ deep observation well (165 ft) I plugged/dry -• shallow observation well (100 ft) V plugged/dry T -r T 1 1 1 1 1 1 1 1 JUL SEP NOV JAN MAR MAY JUL SEP NOV JAN MAR MAY JUL SEP NOV 1986 1987 1988 Figure 21 Piezometric response of the bedrock piezometers (east cluster). Both the shallow and deep wells in the east cluster were obstructed in the initial subsidence event by movements in the overburden. The shallow well was plugged about 70 feet below the surface on March 26, 1 987, about 43 feet below the water level recorded prior to subsidence just 2 days earlier. The shallow well was obstructed about 40 feet from the surface on April 16, 1987. The deep well was obstructed and dry at a depth of 28 feet after the initial failure. The sudden loss of water in the bedrock observation wells may be attributed in part to dilation of the bedrock caused by differential movements and fracturing. The fracturing in the bedrock increases the volume of the unit moni- tored, thereby decreasing the pressure head, as found in subsequent studies in Illinois by Van Roosendaal et al. (1990) and Booth and Spande (1991). The east instrument cluster bedrock wells maintained water levels below their initial readings (above the plugged depths) through the last readings in December 1989. Subsidence affected the hydrogeology of the very low permeability materials of the bedrock over the mined-out area more significantly than that of the drift materials above. Both the bedrock wells and P1 E were still dry more than 2 years after the initial failure. West Cluster The instrument and survey monument layout of the west cluster is shown in figure 8. Virtually all of the data collected from the west instrument cluster were base-line data. Base-line survey coor- dinates were established from ISGS control monuments during the period from April 2 to April 30, 1 987. Base-line data for the MPBX, TDR, and drift and bedrock piezometers were established by numer- ous readings prior to April 30, 1987. Surveying and subsidence characteristics Although the west cluster instrumentation was directly undermined by room-and-pillar mining only, pillar extraction stopped within 10 to 30 feet of part of the transverse monument line (fig. 8). Mining continued for 200 feet using the room-and-pillar mining technique. In July 1987, the maximum subsidence recorded at the west instrument cluster was about 0.13 foot at rebar monument R33, which was closest to the center line of the mined- out area. This monument was located 10 feet off the west edge of the pillar extraction. Unfortunately, all work ceased in the mine as of May 18, 1987. No additional subsidence has been measured at the west instrument cluster since September 1987. Measurements on the rebar monuments were only made with a total station, which produces less accurate elevation readings in comparison to using a level. Also, rebar monuments were short and not anchored or insulated from any freeze- thaw movements. Smaller movements that rapidly diminished westward from the caved face were recorded along the east-west monument line. 24 JUL SEP 1986 NOV JAN MAR — I 1 MAY JUL 1 SEP 1 NOV 1 JAN 1 MAR 1 1 — MAY JUL 1987 1988 SEP NOV Figure 22 Piezometric response of the drift piezometers (west cluster). Hydrogeologic investigations Drift piezometers The water levels in drift piezometers P1W, P3W, and P5W (screens ranged from 15 to 50 feet below the surface), which were located along the side of a small draw, fluctu- ated in a manner somewhat similar to that of the shallow observation well in figure 22. However, the piezometric response of these piezometers, although exaggerated, compared more closely with that of the drift control piezometer, which was located on an interfluve and not affected by the mining. Water levels in the drift piezometers appeared to fluctuate more in response to pre- cipitation (fig. 22), similar to the recorded levels in the piezometers in the east cluster. Bedrock observation wells The water level in the shallow observation well fell about 13 feet from an average depth of 18.0 feet (late March 1987) to 29.6 feet (late September 1987) as shown in figure 23. The well water depth recovered to 18.8 feet by May 1988. The screen of the shallow well was 100 feet below the ground surface, under 50 feet of shale and 50 feet of drift. Piezometric pressures were probably not directly affected by variation in precipitation at this depth. The screen of the deep observation well was about 50 feet above the coal seam at a depth of 203 feet. The water level in this well dropped approximately 26 feet during 15 months from a pre- viously steady depth of around 37.5 feet (period 7/30/86 to 2/3/87) to about 63.3 feet (5/16/88). The water level fell 8 feet rather sharply from March to May 1 987 during subsidence of the east cluster (fig. 22). The water dropped gradually and was apparently leveling off more than 25 feet below presubsidence readings by May 1988. Both the shallow and deep observation wells are about 300 feet from the caved face of the mine workings (fig. 8) and 75 feet from the entryways next to the panel. Solid coal is present on the other side of these entryways. Again, the piezomet- ric pressure drop was apparently not affected by seasonal variations, but was more a function of the fracturing induced by the increased stress field around the mined-out area. This indicates that the mining activity affected the deep aquifer a horizontal distance of at least 300 feet from the caved face. CONCLUSIONS Although only one-half of the instruments were undermined by the high-extraction retreat method, some conclusions may be drawn from this site-specific study. The subsidence event affected the over- burden at the Williamson County research site in several ways. 25 i CO a> in c CO a> E a> s -O CO SOD- S' 490^ 480- 470- 460- | 450- 440- shallow obs. well (100 ft) ♦ — deep obs. well (203 ft) JUL SEP NOV JAN MAR MAY JUL SEP NOV JAN MAR MAY JUL SEP NOV 1986 1987 1988 Figure 23 Piezometric response of the bedrock observation wells (west cluster). 1) Subsidence after the initial overburden failure (survey data) and a reconstructed subsidence profile line perpendicular to the edge of the mined-out area was similar to documented static profiles characteristic of high-extraction retreat subsidence in Illinois. 2) Only one drift piezometer was affected by mine subsidence. Drift piezometer P1E, which was screened just above the bedrock surface, showed a decline in water level as it was undermined. Other drift piezometers showed only fluctuations in the water level related to precipitation. 3) Bedrock observation wells in the east and west clusters responded to the mining activity by a sudden and gradual loss in piezometric pressures, respectively. The initial loss of head in the west cluster bedrock wells was probably caused by dilation of the rock (or microfracturing) in response to changes in the stress field around the mined-out area. The relatively rapid recovery of the shal- low observation well as opposed to the slower recovery of the deep observation well indicates three possible explanations: the attenuation of the fracturing with distance from the caved face, more rapid recharge closer to the ground surface, and different aquifer characteristics at the two monitored levels. The latter may be the most probable explanation. Subsequent studies in Illinois (Van Roosendaal et al. 1 991 , Booth and Spande 1 991 ) have shown that aquifer characteristics as well as lateral extent of the aquifer determine the recovery time after subsidence. 4) Drops in the water level in the bedrock wells of the west instrument cluster indicated that the mining activity affected the deep aquifer for a horizontal distance of at least 300 feet from the caved face. 5) The nearly equal vertical movements of anchors 1 , 2, and 3 indicated that the overburden from 50 to 100 feet beneath the surface moved largely as a contiguous mass. 6) The lack of any further differential vertical movements in the overburden observed with the MPBX indicated that surface subsidence after the initial failure was caused primarily by closure of voids below a depth of 1 50 feet. 7) The break in the TDR cable and the obstruction of the bedrock wells in the east instrument cluster demonstrated the shearing action that occurs near the sides of the panel. This action is a result of differential lateral displacement of the soil and bedrock strata toward the center of the panel due to flexure of the units. Shear offsets were also observed in the piezometers when they were reclaimed. 8) Differential vertical and horizontal movements were associated with interfaces between material of contrasting strengths. These interfaces were located at the base of the fragipan, the drift/bedrock contact, and near the thick sandstone unit in the bedrock where the largest vertical strains were recorded. 26 RECOMMENDATIONS The following are recommendations for performing a similar monitoring program. 1 ) The recovery time of the aquifer should be determined by monitoring on a more continuous basis than was done in this study. Groundwater fluctuations might also be correlated to surface strain if monitoring were more continuous. 2) The TDR weight/anchor design developed during this study is recommended. Use of a flexible bentonite fill in the glacial overburden in order to avoid cable shear failure in the glacial overbur- den or at the contact with the bedrock is also highly recommended. 3) An inclinometer installation is recommended to document lateral movements in the bedrock as the subsidence wave approaches and passes through the instrumented site. 4) Pre- and postsubsidence rock core should be compared to determine changes in fracture fre- quency and locations of increased shearing. The location of fractures would be useful in compar- ing any bedrock movements found using the inclinometer, MPBX, and TDR cables. 5) Glacial material should be sampled using standard split-spoon sampling; standard penetration tests (SPT) should be performed before and after subsidence. 6) One cored borehole should be geophysically logged before and after subsidence to measure differences in shear wave velocity as well as other rock mass properties. 7) All survey monuments, including the control or benchmark monuments, should be constructed alike. All vertical changes should be determined using a level instrument, which has a higher de- gree of accuracy than a total station instrument. 8) A series of packer tests should be conducted before and after subsidence to compare hydrau- lic conductivity. ACKNOWLEDGMENTS The Engineering Geology Section of the Illinois State Geological Survey in Champaign prepared this report under USBM Cooperative Agreement CO 267001, which was initiated under the Illi- nois Mine Subsidence Research Program. It was administered under the technical direction of the U.S. Bureau of Mines Twin Cities Research Center with Larry Powell acting as Technical Pro- ject Officer. Kent Charles and Jose Martinez were the contract administrators for the Bureau of Mines. This report is a summary of the work recently completed as part of the contract during the period from October 1 , 1986, to September 30, 1992. The authors acknowledge the partial funding provided by the Illinois Department of Energy and Natural Resources, the Illinois Coal Development Board, and the Office of Surface Mining. The authors also acknowledge the work of David F. Brutcher, Joseph (Jay) T. Kelleher, Christine E. Ovanic, and students from Northwestern University for their assistance in the field. Billy Anne Trent assisted with manuscript preparation, and Philip J. DeMaris provided several map figures. The authors also thank the land owner Sam Stotlar and the mining company for their assistance and cooperation. Paul B. DuMontelle, former director of the llinois Mine Subsidence Research Pro- gram, assisted in securing the research site. 27 REFERENCES ASTM, 1988, Annual Book of Standards, Section 4 Construction, v. 04.08, Soil and Rock, Build- ing Stones; Geotextiles, 951 p. Bauer, R. A., C. H. Dowding, D. J. Van Roosendaal, B. B. Mehnert, M. B. Su, and K. O'Connor, 1 991 , Application of time domain reflectometry to subsidence monitoring, Final report to Office of Surface Mining: NTIS No. PB91 -22841 1 , 48 p. Booth, C. J., 1986, Strata-movement concepts and the hydrogeological impact of underground coal mining: Ground Water, v. 24, p. 507-515. Booth, C. J., and E. D. Spande, 1990, Piezometric and aquifer property changes above subsid- ing longwall panels, Southern Illinois, in EOS (Trans., Am. Geophys. Union), v. 71, no. 17, p. 506 (AGU Spring Meeting, Baltimore, MD, May 30). Booth, C. J., and E. D. Spande, 1991 , Changes in hydraulic properties of strata over active long- wall mining, Illinois, USA: Proceedings, Fourth International Mine Water Congress, Port- schach, Austria/Lubljana, Slovenia, September, 12 p. Broch, E., and J. A. Franklin, 1972, The point-load strength test: International Journal for Rock Mechanics and Mining Sciences and Geomechanics Abstracts, v. 9, p. 669-697. Brook, N., 1980, Technical note-size correction for point load testing: International Journal for Rock Mechanics and Mining Sciences and Geomechanics Abstracts, v. 17, p. 231-235. Brown, E. T., 1981, Rock Characterization Testing and Monitoring, ISRM Suggested Methods, Published for the Commission on Testing Methods: International Society for Rock Mechanics, Pergamon Press, Oxford, 211 p. Brutcher, D. F., B. B. Mehnert, D. J. Van Roosendaal, and R. A. Bauer, 1990, Rock strength and overburden changes due to subsidence over a longwall coal mining operation in Illinois, in\N. A. Hustrulid and G. A. Johnson, editors, Rock Mechanics Contributions and Challenges, Pro- ceedings of the 31st U.S. Symposium, Balkema, Rotterdam, p. 93-100. Cartwright, K., and C. S. Hunt, 1978, Hydrogeology of underground coal mines in Illinois: ISGS reprint 1978-N, 1978. Reprinted from Proceedings of International Symposium on Water in Mining and Underground Works, Granada, Spain, Sept. 17-22, 20 p. Coe, C. J., and S. M. Stowe, 1984, Evaluating the impact of longwall coal mining on the hydro- logic balance, in D. H. Graves, editor, Proceedings of 1984 Symposium on Surface Mining, Hydrology, Sedimentology, and Reclamation, Lexington, Kentucky, p. 395-403. Conroy, P. J., 1980, Longwall coal mining. Dames and Moore, Engineering Bulletin 52, 1980, p. 13-26. Dowding, C. H., M. B. Su, and K. O'Connor, 1988, Principles of time domain reflectometry ap- plied to measurement of rock mass deformation: International Journal for Rock Mechanics and Mining Science and Geomechanics Abstracts, v. 25, p. 287-297. Dowding, C. H., M. B. Su, and K. O'Connor, 1989, Measurement of rock mass deformation with grouted coaxial antenna cables: Rock Mechanics and Rock Engineering, v. 22, p. 1-23. Duigon, M. T., and M. J. Smigaj, 1985, First report on the hydrologic effects of underground coal mining in southern Garrett County, Maryland: Maryland Geological Survey, Report of Investi- gations 41, 99 p. Engineers International, 1988, Instrumentation to monitor subsidence associated with high- extraction mining in the Illinois Coal Basin: Final report to the U.S. Bureau of Mines, Twin Cit- ies Research Center, Contract No. H0256005, 60 p. Feherenbacher, J. B., and R. T. Odell, 1959, Williamson County Soils, Report 79: Agricultural Ex- periment Station, University of Illinois at Urbana-Champaign, in cooperation with the Soil Con- servation Service, U.S. Department of Agriculture, 72 p. Garritty, P., 1982, Water percolation into fully caved longwall faces, Proceedings of the Sympo- sium on Strata Mechanics held in Newcastle-upon-Tyne: Developments in Geotechnical Engi- neering, v. 32, p. 25-29. GeoTechnical Graphics System, 1991, Software (version 3.1): GeoTechnical Graphics, Berkeley, CA. 28 Horberg, C. L, 1950, Bedrock Topography of Illinois: Illinois State Geological Survey, Bulletin 73, 1 1 1 p. Hunt, S. R., 1980, Surface subsidence due to coal mining in Illinois: Ph.D. thesis, University of Illi- nois at Urbana-Champaign, 129 p. Ingram, D. K., and G. M. Molinda, 1988, Relationship between horizontal stresses and geologic anomalies in two coal mines in southern Illinois: U.S. Bureau of Mines, Rl 9189, p. 17. International Society for Rock Mechanics, 1985, Commission of Testing Methods (J.A. Franklin coordinator): International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts, v. 22, no. 2, p. 51-60. Kratzsch, H., 1983, Mining Subsidence Engineering: Springer-Verlag, New York, 543 p. Krausse, H. F., H. H. Damberger, W. J. Nelson, S. R. Hunt, C. T. Ledvina, C. G. Treworgy, and W. A. White, 1979, Roof Strata of the Herrin (No. 6) Coal Member in Mines of Illinois: Their Geol- ogy and Stability, Summary Report: Illinois State Geological Survey, Illinois Minerals Note 72, 54 p. Leighton, M. M., G. E. Ekblaw, and C. L. Horberg, 1948, Physiographic Divisions of Illinois: Illinois State Geological Survey, Report of Investigations 129, 19 p. MacClintock, P., 1929, Physiographic Divisions of the Area Covered by the lllinoian Driftsheet in Southern Illinois: Illinois State Geological Survey, Report of Investigations 19, 57 p. Ming-Gao, C, 1982, A study of the behaviour of overlying strata in longwall mining and its appli- cation to strata control, in I. W. Farmer, editor, Proceedings of the Symposium on Strata Mechanics: Elsevier, New York, p. 13-17. Nelson, W. J., 1979, Geologic effects of the Walshville channel on coal mining conditions in southern Illinois, Depositional and structural history of the Pennsylvanian System of the Illinois Basin Part 2: Invited Papers, Field trip 9/Ninth International Congress of Carboniferous Strati- graphy and Geology, p. 151-158. Nelson, W. J., and R. A. Bauer, 1987, Thrust faults in southern Illinois basin — result of contempo- rary stress? Geological Society of America Bulletin, v. 98, p. 302-307. Nelson, W. J., and H. F. Krausse, 1981, The Cottage Grove Fault System in Southern Illinois: Illi- nois State Geological Survey, Circular 522, 65 p. Nieto, A. S., 1979, Evaluation of damage potential to earth dam by subsurface coal mining at Rend Lake, Illinois: Ohio River Valley Soils Seminar; Geotechnics of Mining. Lexington, KY, Oct. 5, p. 9-18. Owili-Eger, A. S., 1983, Geohydrologic and hydrogeochemical impacts of longwall coal mining on local aquifers: SME-AIME Fall Meeting, Salt Lake City, UT. Preprint No. 83-376, 16 p. Pauvlik, C. M., and S. P. Esling, 1987, The effects of longwall mining subsidence on the ground- water conditions of a shallow, unconfined aquitard in Southern Illinois, in Proceedings, 1987 National Symposium on Mining, Hydrology, Sedimentology, and Reclamation, Lexington, Ken- tucky, December 7-11, University of Kentucky, Lexington, p. 189-195. Pennington, D., J. G. Hill, G. J. Burgdorf, and D. R. Price, 1984, Effects of longwall mine subsi- dence on overlying aquifers in Western Pennsylvania: U.S. Bureau of Mines OFR 142-84, 129 p. Pryor, W. A., 1953, Groundwater possibilities for municipal supply of Pittsburg, Williamson County: Illinois State Geological Survey, Division of Ground Water Geology and Geophysical Exploration, unpublished geologic report. Sasman, R. T., 1953, Groundwater resources at Pittsburg, Williamson County: State Water Sur- vey Division, Illinois Department of Registration and Education, unpublished report. Sloan, P., and R. C. Warner, 1984, A case study of groundwater impact caused by underground mining, in D. H. Graves, editor, Proceedings of 1984 Symposium on Surface Mining, Hydrol- ogy, Sedimentology and Reclamation, Lexington, Kentucky, p. 113-120. Van Roosendaal, D. J., D. F. Brutcher, B. B. Mehnert, J. T. Kelleher, and R. A. Bauer, 1990, Overburden deformation and hydrologic changes due to longwall mine subsidence in Illinois, in Y. P. Chugh, editor, Proceedings of 3rd Conference on Ground Control Problems in the Illi- nois Coal Basin: Southern Illinois University at Carbondale, p. 73-82. 29 Van Roosendaal, D. J., B. B. Mehnert, J. T. Kelleher, and C. E. Ovanic, 1991, Three dimensional ground movements associated with longwall mine subsidence in Illinois: Association of Engi- neering Geologists 34th Annual Meeting, Chicago, IL, p. 815-826. Whitworth, K. R., 1982, Induced changes in permeability of coal measure strata as an indicator of the mechanics of rock deformation above a longwall coal face, in I. W. Farmer, editor, Pro- ceedings of the Symposium on Strata Mechanics, Elsevier, New York, p. 18-24. 30 APPENDIXES A Overburden Characterization Rock Mechanics Laboratory Results Geotechnical Core Log B MPBX Readings and Calculations for Both Clusters East Cluster MPBX Readings and Calculations West Cluster MPBX Readings and Calculations C Surveying Data Survey Coordinates for East Cluster Instruments and Monuments Survey Coordinates for West Cluster Instruments and Monuments D Elevation Changes due to Subsidence Elevation Changes of East Cluster Instruments Elevation Changes of West Cluster Instruments E Water Level Readings and Precipitation Data Piezometer Water Level Readings, East Cluster Piezometer Water Level Readings, West Cluster Precipitation Data from Marion Station 31 APPENDIX A Overburden Characterization UJ CO UJ > z LU > 2 rr > cr -i cr LU ro O X < o i- o i LU o (0 m 7" o 3 LU CD cn CM CM co co o O id c\i o in CM ID co CM CD CM CM CD CM CM * * ■v cm CM co CD CM 00 ID CM CD CO CM CM 1^ CD CM o CM * * CD CM CM ID CM AVERAGE INDIRECT TENSILE STRENGTH (psi) * * o CO CO CO 2 * * CO CM * * CM o * * •* CM CO CM cm T— ID O CD O) ID CO O) ID CD * * CD ID CM CM ^1" AVERAGE T500 (MPa) * * CD a CO 0) CO * * CD «* CO * * ID * * co ID en CM co CO CD N co CO CO ID CD CM * * CD CO 1^ CM CM AVERAGE AXIAL POINT LOAD INDEX (psi) * * CD to CM co * * 05 CO * * O o CM. * * CNI T— co ID CD CD co" CD CD CD CNI CD O CD * * CO CO MOISTURE CONTENT @qu (%) CM c\i co CM en CM CO o> co CM <* CM CO CD O o 0) o O) d en CD CO CO d s * 1^ CM CM CO f~- * * 3 crj co CD d * * co d 3 Hf 03 CM co CD N co CD CD N CM co CO CD" in co in" CM ID CM o CO" CO o 0) CD" ID CO CD" co r- CD co" co co co <*" -* ID * * * * o CM CO ID" * * oo CO io" * LU O 0- cr f- X CO X CO X CO CO CO CO CO CO _l H co 1- _J CO co h- _l CO H CO 1- _l CO CO CO l- co f- _l CO CO _1 CO CO X CO X CO X CO X CO X CO SAMPLE ID (DEPTH) (ft) CO en N o CO 01 o 0) en CO CO o o <* CO CM m CO CD CO s CD O o-i CO CD O en o CO 0) CD CM CM o CM co CM o CO co CM oi co CM CO CM CD J3 CO 'co > CO <0 CD c o CD c o 7n CD c o a. F 0) CO r CO c/i CD F (0 .c m II CO CO CO 1— _l O Z II II CO H II X to _J CO « CO to CO _l 32 GEOLOGICAL BORING LOG: Pre-sub Core; 10' from vert; West Cluster Page 1 of 14 PROJECT: IMStfP Williamson Cnty High-Extraction Retreat Site SURF ELEV: 509.75 FT LOCATION: NWX, SWX, S6, T9S, R4E. Williamson Cnty, IL TOTAL DEPTH: 264.3 FT LOGGED BY: E. Gefell, R. Bauer, T. Honeycutt METHOD: NX-wireline core DATE DRILLED: June 10-12, 1986 Cl ■■£ PC > o Si ■••• oc ■.'• Oc <. oc a i Oc => „ °c oc >■■•« oc > \i OC ■■'» OC ft . tf Oo o oc »■-•' „ Oc > o oc >•■•• Oc o Oc o Oc * o Oc a „ oo i Oc °-i i oc o i Oc -i i Oc ° ••.<, roc o • oc » i Oc P 'o J"' a . oc •■■• Oc *■■• Oc oc o OC 9 «, oc 3 ■"■• oc ■•• Oc 3 «, Oc ft „ Drilling Data Core Recov (X) 25 50 75 ROD 25 50 75 i i i Fractures per foot 12 3 4 Joints Description GLACIAL TILL: less than 3 ft Loess overlying Illinosian till, some sandy zones, clayey at bottom 5- 10- 15- 20- Illinois State Geological Survey Illinois Mine Subsidence Research Program 615 East Peabody Orive, Champaign, IL 61820 (217) 333-4747 33 GEOLOGICAL BORING LOG: Pre-sub Core; 10" from vert; West Cluster Page 2 of 14 PROJECT: IMSRP Williamson Cnty High-Extraction Retreat Site SURF ELEV: 509.75 FT LOCATION: NWX, SWX, S6, T9S, R4E. Williamson Cnty, IL TOTAL DEPTH: 264.3 FT LOGGED BY: E. Gefell, R. Bauer, T. Honeycutt METHOD: NX-wireline core OATE DRILLED: June 10-12, 1986 Cl 0} St 20- Oescription Drilling Data Core Recov (X) 25 50 75 ROD 25 50 75 Fractures per foot 12 3 4 Joints Description 25- 30- 35- 40- oc ' o or. Ofl oc oc ' o oc OC oc Ofl 0.( Ofl oc Ofl • e oc &-.. oc v.i OC OC oc oc » o oc oc ° o . OC »•■• • OC • oc oc o Oc oc > o Oc p ■■■» OC > •••• oc o Oc •■.. oc *■.. OC i oc . roc '■■• OC . oc oc ° '■:» oc o oc P-o £1 Illinois State Geological Survey Illinois Mine Subsidence Research Program 615 East Peabody Drive, Champaign, IL 61820 (217) 333-4747 34 GEOLOGICAL BORING LOG: Pre-sub Core; 10' from vert; West Cluster Page 3 of 14 PROJECT: IMSRP Williamson Cnty High-Extraction Retreat Site SURF ELEV: 509.75 FT LOCATION: NWX, SWH, 56, T9S, R4E. Williamson Cnty, IL TOTAL DEPTH: 264.3 FT LOGGED BY: E. Gefell, R. Bauer, T. Honeycutt METHOD: NX-wireline core DATE DRILLED: June 10-12, 1986 St 40- Description Joints Description 45- 50- MUOSTONE: mottled gray-brown, soft, some fractures, some harder silty zones SHALE: gray; med-soft 55- SHALE: gray-black to black, med-soft 51.25: no filling, brown staining, uneven, slickensides, 35' dip 51.75: no filling, uneven, slickensides, 55' dip 53.25: no filling, uneven, slickensides, 40' dip SHALE: med It gray, si silty 56.83: no filling, planar, slickensides, 30' dip 57.0: no filling, uneven, slickensides, 40' dip 60- SHALE: med It gray, calcareous, thinly lam with siderite nodules, some silt Illinois State Geological Survey Illinois Mine Subsidence Research Program 615 East Peabody Drive, Champaign, IL 61820 (217) 333-4747 35 GEOLOGICAL BORING LOG: Pre-sub Core; 10" from vert; West Cluster Page 4 of 14 PROJECT: IMSRP Williamson Cnty High-Extraction Retreat Site SURF ELEV: 509.75 FT LOCATION: NWX, SWX, S6, T9S, R4E, Williamson Cnty, IL TOTAL DEPTH: 264.3 FT LOGGED BY: E. Gefell, R. Bauer, T. Honeycutt METHOD: NX-wireline core DATE DRILLED: June 10-12, 1986 Q. a) St 60- Description Joints Description SHALE: med. It gray, thinly lam with silt and shale 65- SHALE: med dk gray to dk gray, thinly lam, lenticular It gray banding, some 2 to 3 in thick siderite bands, becoming less silty downward 70- 75- 80- Illinois State Geological Survey Illinois Mine Subsidence Research Program 615 East Peabody Drive, Champaign, IL 61820 (217) 333-4747 36 GEOLOGICAL BORING LOG: Pre-sub Core; 10' from vert; West Cluster Page 5 of 14 PROJECT: IMSRP Williamson Cnty High-Extraction Retreat Site SURF ELEV: 509.75 FT LOCATION: NWK, SNK, S6, T9S, R4E, Williamson Cnty, IL TOTAL DEPTH: 264.3 FT LOGGED BY: E. Gefell. R. Bauer, T. Honeycutt METHOD: NX-wireline core DATE DRILLED: June 10-12, 1986 O. d) Sit 80- Description Joints Description 85- 90- 95- 100- SHALE: med to dk gray, lam with some greenish It gray shale bands SHALE: black, carbonaceous, fissile, phosphate lenses at 89.8, sharp contact to si less carbonaceous black shale COAL: normally bright banded, calcite filled cleat, pyritic at base SHALE: med gray, weak SHALE: med It gray SHALE: dk gray, si silty, lam with silty, micaceous layers 90.25: no filling, planar, rough. 85* dip .9-96.2: no filling, planar-wavy, slickensides, 15-85' dip, underclay with numerous joints Illinois State Geological Survey Illinois Mine Subsidence Research Program 615 East Peabody Drive, Champaign, IL 61820 (217) 333-4747 37 GEOLOGICAL BORING LOG: Pre-sub Core; 10' from vert; West Cluster Page 6 of 14 PROJECT: IMSRP Williamson Cnty High-Extraction Retreat Site SURFELEV: 509.75 FT LOCATION: NWM, SWX, S6, T9S, R4E, Williamson Cnty, IL TOTAL OEPTH: 264.3 FT LOGGEO BY: E. Gefell, R. Bauer, T. Honeycutt METHOD: NX-wireline core DATE DRILLEO: June 10-12, 1986 St 100- Oescription Joints Description 105- 110- 115- 120- SANOSTONE: med It to It gray, si argillaceous and micaceous SANDSTONE: med It to It gray, si argillaceous and micaceous, some thin shale partings SANDSTONE: med It to It gray, coarser and more micaceous, fine to med grained SANOSTONE: med It to It gray, coarser and more micaceous, fine to med grained, few shale partings -109.4: completely filled with white calcite, wavy, rough, 85-90' dip Illinois State Geological Survey Illinois Mine Subsidence Research Program 615 East Peabody Drive. Champaign, IL 61820 (217) 333-4747 38 GEOLOGICAL BORING LOG: Pre-sub Core; 10" from vert; West Cluster Page 7 of 14 PROJECT: IMSRP Williamson Cnty High-Extraction Retreat Site SURF ELEV: 509.75 FT LOCATION: NWM, SWX, S6, T9S, R4E, Williamson Cnty, IL TOTAL DEPTH: 264.3 FT LOGGED BY: E. Gefell, R. Bauer, T. Honeycutt METHOD: NX-wireline core DATE ORILLED: June 10-12, 1986 o — 120- Description Joints Description 125- 130- 135- 140- SANDSTONE: med It to It gray, coarser and more micaceous, fewer clay partings, less clay SANDSTONE: med It to It gray, coarser and more micaceous, few clay partings and iron staining SANOSTONE: med It to It gray, coarser and more micaceous, fine to med grained SANOSTONE: med to It gray, med to coarse grained bands of micaceous, carbonaceous material Illinois State Geological Survey Illinois Mine Subsidence Research Program 615 East Peabody Drive, Champaign, IL 61820 (217) 333-4747 39 GEOLOGICAL BORING LOG: Pre-sub Core; IO - from vert; West Cluster Page 8 of 14 PROJECT: IMSRP Williamson Cnty High-Extraction Retreat Site SURF ELEV: 509.75 FT LOCATION: NWH, SWM, S6, T9S, R4E, Williamson Cnty, IL TOTAL DEPTH: 264.3 FT LOGGED BY: E. Gefell, R. Bauer, T. Honeycutt METHOD: NX-wireline core DATE DRILLED: June 10-12, 1986 St 140- Oescription Joints Description 145- 150- 155- 160- SHALE: med dk to dk gray, fissile, some lam of It gray shale H46.6: no filling, planar, slickensides, 35' dip COAL: argillaceous SHALE: med gray to med dk gray, grayish-black lam LIMESTONE: very It gray, to med dk gray, argillaceous near top, biomicrite. crinoid stems, (PIASA) SHALE: dk gray to grayish-black, argillaceous SHALE: med gray to med dk gray, fissile, si calcareous at top SHALE: grayish-black, carbonaceous, fissile, some lam COAL: black, argillaceous SHALE: med gray, si silty, few silt lam Illinois State Geological Survey Illinois Mine Subsidence Research Program 615 East Peabody Drive, Champaign, IL 61820 (217) 333-4747 40 GEOLOGICAL BORING LOG: Pre-sub Core; 10' from vert; West Cluster Page 9 of 14 PROJECT: IMSRP Williamson Cnty High-Extraction Retreat Site SURF ELEV: 509.75 FT LOCATION: NWX, SWH, S6, T9S, R4E, Williamson Cnty, IL TOTAL DEPTH: 264.3 FT LOGGED BY: E. Gefell, R. Bauer, T. Honeycutt METHOD: NX-wireline core DATE DRILLED: June 10-12, 1986 Cl m 160- Description Joints Description 165- 170- 175- 180- SILTSTONE: It gray, argillaceous at top, highly lam with silt layers, becoming med to med dark gray downward H67.4: no filling, wavy, slickensides, 30' dip SILTSTONE: med to med dk gray, highly lam with silt layers, 1 in band of siderite at top SANDSTONE-S1LTSTONE: med It gray silt-sand, med dk gray shale, inter lam, very thin layers, becoming darker downwards SHALE: med to dk gray, lam COAL: argillaceous, fissile, black SANDSTONE-SILTSTONE: med gray, siderite concretions, bands Illinois State Geological Survey Illinois Mine Subsidence Research Program 615 East Peabody Drive, Champaign, IL 61820 (217) 333-4747 41 GEOLOGICAL BORING LOG: Pre-sub Core; 10' from vert; West Cluster Page 10 of 14 PROJECT: IMSRP Williamson Cnty High-Extraction Retreat Site SURF ELEV: 509.75 FT LOCATION: NWX, SWK, S6, T9S, R4E, Williamson Cnty, 1L TOTAL DEPTH: 264.3 FT LOGGED BY: E. Gefell, R. Bauer, T. Honeycutt METHOO: NX-wireline core DATE DRILLED: June 10-12, 1986 JZ — O. u Sit 180- Description Joints Description 185- 190- 195- 200- COAL: argillaceous CLAYSTONE-SHALE: med dk gray to dk gray in lam LIMESTONE: buff color, argillaceous, fine grained, irregularly shaped clay voids near top SHALE: med It gray. soft, becomes silly downward SHALE: med It gray, soft, lam with silt SILTSTONE: lam shale-siltstone SANOSTONE: It brown to It gray, fine ti med grained, lam with shale H85.3-185.7: no filling, wavy, slickensides, 30-45' dip, underclay with numerous joints Illinois State Geological Survey Illinois Mine Subsidence Research Program 615 East Peabody Drive, Champaign, IL 61820 (217) 333-4747 42 GEOLOGICAL BORING LOG: Pre-sub Core; 10' from vert; West Cluster Page 11 of 14 PROJECT: IMSRP Williamson Cnty High-Extraction Retreat Site SURF ELEV: 509.75 FT LOCATION: NWH, SWK, S6, T9S, R4E, Williamson Cnty, IL TOTAL DEPTH: 264.3 FT LOGGED BY: E. Gefell, R. Bauer, T. Honeycutt METHOD: NX-wireline core DATE DRILLED: June 10-12, 1986 St 200- Description Joints Description SHALE: med dk gray, some silt lam, few siderite bands 205- SHALE: med dk gray, more silty, lam silt and shale 210- 215- 220- Illinois State Geological Survey Illinois Mine Subsidence Research Program 615 East Peabody Drive, Champaign, IL 61820 (217) 333-4747 43 GEOLOGICAL BORING LOG: Pre-sub Core; 10' from vert; West Cluster Page 12 of 14 PROJECT: IMSRP Williamson Cnty High-Extraction Retreat Site SURFELEV: 509.75 FT LOCATION: NWK, SWH, S6, T9S, R4E, Williamson Cnty, IL TOTAL DEPTH: 264.3 FT LOGGED BY: E. Gefell, R. Bauer, T. Honeycutt METHOD: NX-wireline core DATE ORILLED: June 10-12, 1986 Q. a) St 220- Description Joints Description 225- 230- 235- 240- LIMESTONE: med to med dk gray, fossiliferous COAL: normally bright banded LIMESTONE: med gray to med It gray, fossiliferous, argillaceous (BRERETON) SHALE: dk gray to black, carbonaceous, fissile, thin phosphate bands or lenses (ANNA) SHALE: dk gray to med dk gray, si fissile, siderite bands with pyrite nodule and vert cleat calcite fill (ENER6Y) Illinois State Geological Survey Illinois Mine Subsidence Research Program 615 East Peabody Drive, Champaign, IL 61820 (217) 333-4747 44 GEOLOGICAL BORING LOG: Pre-sub Core; 10' from vert; West Cluster Page 13 of 14 PROJECT: IMSRP Williamson Cnty High-Extraction Retreat Site SURF ELEV: 509.75 FT LOCATION: NWH, SWH, S6, T9S, R4E. Williamson Cnty, IL TOTAL DEPTH: 264.3 FT LOGGED BY: E. Gefell, R. Bauer, T. Honeycutt METHOD: NX-wireline core DATE DRILLED: June 10-12, 1986 Q. qj St 240- Description Joints Description 245- 250- 255- 260- COAL: normally bright banded, vert cleat with calcite (HERRIN No. 6) CLAYSTONE: med to med dk gray, carbonaceous plant impressions, si calcareous LIMESTONE: buff to It gray, argillaceous, nodular underclay limestone, fine grained, nodules increase in size and less claystone 256.87: no filling, planar, smooth, 45' dip Illinois State Geological Survey Illinois Mine Subsidence Research Program 615 East Peabody Drive, Champaign, IL 61820 (217) 333-4747 45 GEOLOGICAL BORING LOG: Pre-sub Core; 10' from vert; West Cluster Page 14 of 14 PROJECT: IMSRP Williamson Cnty High-Extraction Retreat Site SURF ELEV: 509.75 FT LOCATION: NWH, SWH, S6, T9S, R4E, Williamson Cnty, IL TOTAL DEPTH: 264.3 FT LOGGED BY: E. Gefell, R. Bauer, T. Honeycutt METHOD: NX-wireline core DATE DRILLED: June 10-12, 1986 Cl 0) St 260- Description Drilling Data Fractures per foot 12 3 4 J I I I Joints Description SHALE: med gray, limestone nodules 265- TOTAL DEPTH: 264.3 FT J 270- 275- 280- Illinois State Geological Survey Illinois Mine Subsidence Research Program 615 East Peabody Drive, Champaign, IL 61820 (217) 333-4747 46 APPENDIX B MPBX Readings and Calculations for Both Clusters WILLIAMSON COUNTY EAST CLUSTER MPBX READINGS [in feet] ROD#1 [length = 50 ft] DATE ROD TIP SURFACE ANCHOR TOTAL READING ELEV ELEV ANCHOR CHANGE 1986 SEPT 9 -0.080 523.050 472.970 „ SEPT 20 -0.080 523.050 472.970 0.000 DEC 10 -0.079 523.050 472.971 0.001 1987 FEB 2 -0.079 523.050 472.971 0.001 MAR 24 -0.080 523.050 472.970 0.000 MAR 27 -0.403 521 .226 470.823 -2.147 MAR 31 -0.401 521 .098 470.697 -2.273 APR 1 -0.400 521 .098 470.698 -2.272 APR 2 -0.400 521 .098 470.698 -2.272 APR 3 -0.403 521 .025 470.622 -2.348 APR 16 -0.287 521 .025 470.738 -2.232 APR 21 -0.280 520.056 469.776 -3.194 APR 23 -0.279 520.056 469.777 -3.193 APR 29 -0.278 520.01 1 469.733 -3.237 MAY 14 -0.278 519.990 469.712 -3.258 MAY 27 -0.278 519.990 469.712 -3.258 MAY 28 -0.280 519.990 469.710 -3.260 JULY 22 -0.280 519.937 469.657 -3.313 SEPT 24 -0.280 519.926 469.646 -3.324 1988 JAN 12 -0.28 519.887 469.607 -3.364 OCT 11 -0.274 519.887 469.613 -3.358 1989 APR 27 -0.2728 519.7776 469.505 -3.465 ROD #2 DATE ROD TIP SURFACE ANCHOR TOTAL [length = 75 ft] READING ELEV ELEV ANCHOR CHANGE 1986 SEPT 9 -0.081 523.050 447.969 -- SEPT 20 -0.082 523.050 447.968 -0.001 DEC 10 -0.081 523.050 447.969 0.000 1987 FEB 2 -0.081 523.050 447.969 0.000 MAR 24 -0.082 523.050 447.968 -0.001 MAR 27 -0.403 521 .226 445.823 -2.146 MAR 31 -0.400 521 .098 445.698 -2.271 APR 1 -0.400 521 .098 445.698 -2.271 APR 2 -0.400 521.098 445.698 -2.271 APR 3 -0.403 521 .025 445.622 -2.347 APR 16 -0.289 521 .025 445.736 -2.233 APR 21 -0.284 520.056 444.772 -3.197 APR 23 -0.280 520.056 444.776 -3.193 APR 29 -0.280 520.01 1 444.731 -3.238 MAY 14 -0.280 519.990 444.710 -3.259 MAY 27 -0.282 519.990 444.708 -3.261 MAY 28 -0.281 519.990 444.709 -3.260 JULY 22 -0.285 519.937 444.652 -3.317 SEPT 24 -0.283 519.926 444.643 -3.326 1988 JAN 12 -0.283 519.887 444.604 -3.365 OCT 11 -0.279 519.887 444.608 -3.361 1989 APR 27 -0.2777 519.7776 444.500 -3.469 continued 47 WILLIAMSON COUNTY EAST CLUSTER MPBX READINGS [in feet] ROD #3 DATE ROD TIP SURFACE ANCHOR TOTAL [length = 100 ft] READING ELEV ELEV ANCHOR CHANGE 1986 SEPT 9 -0.077 523.050 422.973 — SEPT 20 -0.077 523.050 422.973 0.000 DEC 10 -0.077 523.050 422.973 0.000 1987 FEB 2 -0.077 523.050 422.973 0.000 MAR 24 -0.077 523.050 422.973 0.000 MAR 27 -0.397 521 .226 420.829 -2.144 MAR 31 -0.396 521.098 420.702 -2.271 APR 1 -0.396 521 .098 420.702 -2.271 APR 2 -0.396 521 .098 420.702 -2.271 APR 3 -0.397 521 .025 420.628 -2.345 APR 16 -0.287 521 .025 420.738 -2.235 APR 21 -0.285 520.056 419.771 -3.202 APR 23 -0.282 520.056 419.774 -3.199 APR 29 -0.281 520.01 1 419.730 -3.243 MAY 14 -0.281 519.990 419.709 -3.264 MAY 27 -0.280 519.990 419.710 -3.263 MAY 28 -0.281 519.990 419.709 -3.264 JULY 22 -0.287 519.937 419.650 -3.323 SEPT 24 -0.286 519.926 419.640 -3.333 1988 JAN 12 -0.285 519.887 419.602 -3.371 OCT 11 -0.281 519.887 419.606 -3.367 1989 APR 27 -0.2788 519.7776 419.499 -3.474 ROD #4 DATE ROD TIP SURFACE ANCHOR TOTAL [length = 125 ft] READING ELEV ELEV ANCHOR CHANGE 1986 SEPT 9 -0.072 523.050 397.978 — SEPT 20 -0.073 523.050 397.977 -0.001 DEC 10 -0.073 523.050 397.977 -0.001 1987 FEB 2 -0.074 523.050 397.976 -0.002 MAR 24 -0.074 523.050 397.976 -0.002 MAR 27 -1 .698 521 .226 394.528 -3.450 MAR 31 -1 .703 521 .098 394.395 -3.583 APR 1 -1.700 521 .098 394.398 -3.580 APR 2 -1.700 521 .098 394.398 -3.580 APR 3 -1 .698 521 .025 394.327 -3.651 APR 16 -1 .600 521 .025 394.425 -3.553 APR 21 -1.598 520.056 393.458 -4.520 APR 23 -1 .595 520.056 393.461 -4.517 APR 29 -1 .595 520.01 1 393.416 -4.562 MAY 14 -1.594 519.990 393.396 -4.582 MAY 27 -1 .599 519.990 393.391 -4.587 MAY 28 -1 .595 519.990 393.395 -4.583 JULY 22 -1 .605 519.937 393.332 -4.646 SEPT 24 -1.6 519.926 393.326 -4.652 1988 JAN 12 -1 .605 519.887 393.282 -4.696 OCT 11 -1 .593 519.887 393.294 -4.684 1989 APR 27 -1 .5885 519.7776 393.189 -4.789 continued 48 WILLIAMSON COUNTY EAST CLUSTER MPBX READINGS [in feet] ROD #5 DATE ROD TIP SURFACE ANCHOR TOTAL [length = 150 ft] READING ELEV ELEV ANCHOR CHANGE 1986 SEPT 9 -0.075 523.050 372.975 — SEPT 20 -0.075 523.050 372.975 0.000 DEC 10 -0.076 523.050 372.974 -0.001 1987 FEB 2 -0.077 523.050 372.973 -0.002 MAR 24 -0.077 523.050 372.973 -0.002 MAR 27 -2.123 521 .226 369.103 -3.872 MAR 31 -2.130 521 .098 368.968 -4.007 APR 1 -2.127 521 .098 368.971 -4.004 APR 2 -2.128 521 .098 368.970 -4.005 APR 3 -2.123 521 .025 368.902 -4.073 APR 16 -2.008 521 .025 369.017 -3.958 APR 21 -2.010 520.056 368.046 -4.929 APR 23 -2.004 520.056 368.052 -4.923 APR 29 -2.008 520.01 1 368.003 -4.972 MAY 14 -2.008 519.990 367.982 -4.993 MAY 27 -2.008 519.990 367.982 -4.993 MAY 28 -2.006 519.990 367.984 -4.991 JULY 22 -2.012 519.937 367.925 -5.050 SEPT 24 -2.009 519.926 367.917 -5.058 1988 JAN 12 -2.009 519.887 367.878 -5.097 OCT 11 -2.001 519.887 367.886 -5.089 1989 APR 27 -1.9948 519.7776 367.783 -5.192 ROD #6 DATE ROD TIP SURFACE ANCHOR TOTAL [length = 175 ft] READING ELEV ELEV ANCHOR CHANGE 1986 SEPT 9 -0.056 523.050 347.994 _. SEPT 20 -0.056 523.050 347.994 0.000 DEC 10 -0.055 523.050 347.995 0.001 1987 FEB 2 -0.056 523.050 347.994 0.000 MAR 24 -0.057 523.050 347.993 -0.001 MAR 27 -1.120 521 .226 345.106 -2.888 MAR 31 -1.122 521 .098 344.976 -3.018 APR 1 -1.120 521 .098 344.978 -3.016 APR 2 -1.123 521 .098 344.975 -3.019 APR 3 -1.120 521 .025 344.905 -3.089 APR 16 -0.998 521 .025 345.027 -2.967 APR 21 -0.996 520.056 344.060 -3.934 APR 23 -0.995 520.056 344.061 -3.933 APR 29 -0.995 520.01 1 344.016 -3.978 MAY 14 -0.994 519.990 343.996 -3.998 MAY 27 -0.993 519.990 343.997 -3.997 MAY 28 -0.992 519.990 343.998 -3.996 JULY 22 -0.995 519.937 343.942 -4.052 SEPT 24 -0.995 519.926 343.931 -4.063 1988 JAN 12 -0.995 519.887 343.892 -4.102 OCT 11 -0.989 519.887 343.898 -4.096 1989 APR 27 -0.9844 519.7776 343.793 -4.201 49 WILLIAMSON COUNTY WEST CLUSTER MPBX HEADINGS ROD#1 TOTAL [length - 50 ft] DATE ROD TIP SURFACE ANCHOR ANCHOR READING ELEV ELEV CHANGE 1966 SEPT 9 0.007 509.613 459.620 — SEPT 20 0006 509.613 459.621 0.001 DEC 11 0008 509613 459.619 -0.001 1967 FEB 2 0004 509613 459 617 -0.003 APR 14 0004 509.613 459617 -0 003 APR 22 002 509613 459615 -0 005 APR 30 0002 509613 459.615 -0.005 MAY 13 0001 509613 459614 -0 006 RO0#2 TOTAL [length - 75 ft] DATE ROD TIP SURFACE ANCHOR ANCHOR READING ELEV ELEV CHANGE 1686 SEPT 9 0.050 509.613 434.663 — SEPT 20 0.050 509613 434.663 0.000 0EC11 0.047 509.613 434.660 -0 003 1987 FEB 2 046 506.613 434.659 -0.004 APR 14 046 509613 434 659 -0 004 APR 22 0.043 506.613 434.656 -0.007 APR 30 0.045 509813 434 658 -0.005 MAY 13 0.046 509613 434 659 -0 004 ROD #3 TOTAL [length = 100 ft] DATE ROD TIP SURFACE ANCHOR ANCHOR READING ELEV ELEV CHANGE 1986 SEPT 9 150 509.813 459 763 — SEPT 20 150 509.613 459 763 000 DEC 11 0.149 509.613 459762 -0.001 1987 FEB 2 0.149 509.613 456.762 -0.001 APR 14 146 509613 459 759 -0 004 APR 22 0.146 509613 459759 -0 004 APR 30 0.149 509613 459 762 -0 001 MAY 13 148 509613 459 761 -0 002 ROD #4 TOTAL [length = 125 ft] DATE ROD TIP SURFACE ANCHOR ANCHOR READING ELEV ELEV CHANGE 1986 SEPT 9 170 509613 434783 — SEPT 20 0.170 509613 434.783 000 DEC 11 166 509.613 434.779 -0 004 1987 FEB 2 0.168 509.613 434.781 -0.002 APR 14 0.161 509613 434 774 -0 009 APR 22 164 509613 434.777 -0.006 APR 30 165 509613 434.778 -0 005 MAY 13 164 509613 434777 -0 006 ROD #5 TOTAL [length ■ 150 ft] DATE ROD TIP SURFACE ANCHOR ANCHOR READING ELEV ELEV CHANGE 1986 SEPT 9 112 509613 456 725 — SEPT 20 0.112 509613 459 725 0000 DEC 11 0.109 509613 459 722 -0 003 1987 FEB 2 0.110 509.613 459.723 -0 002 APR 14 0.107 509 613 459.720 -0 005 APR 22 109 509613 459.722 -0 003 APR 30 0.110 509613 459 723 -0 002 MAY 13 0.111 509613 459.724 -0 001 ROD #6 TOTAL [length ■ 175 ft] DATE ROD TIP SURFACE ANCHOR ANCHOR READING ELEV ELEV CHANGE 1966 SEPT 9 0.083 509613 434 696 SEPT 20 083 509813 434 696 0000 DEC 11 0081 509613 434 694 -0.002 1987 FEB 2 079 509613 434 692 -0 004 APR 14 078 506613 434 691 -0 005 APR 22 0.077 509613 434 690 -0 006 APR 30 0079 509613 434 692 -0 004 MAY 13 0079 509613 434 692 -0 004 50 APPENDIX C Surveying Data COORDINATES FOR THE EAST CLUSTER INSTRUMENTS & MONUMENTS WILLIAMSON COUNTY V»* Itftf *tf S<> -0> V $° V && ^ INSTRUMENT/ MONUMENT NORTHINGS EASTINGS ELEVATIONS MPBX DATE ■4082.360 32160.930 523.330 E.I.* -4081.694 32161.258 521.226 3-27-87 •4081.717 32161.170 521.025 4-03-87 ■4081.795 32160.475 520.056 4-21-87 4081.814 32160.443 520.01 1 4-29-87 •4081.872 32160.379 519.990 5-14-86 4081.800 32160.423 519.937 7-22-87 4081.793 32160.509 519926 9-24-87 4081 849 32160.437 519.887 1-12-88 INSTRUMENT/ MONUMENT NORTHINGS EASTINGS ELEVATIONS DATE P1E ■4116.950 32158.930 522490 E.I.' 4116.901 32159 175 522.256 3-27-87 4116.910 32159 173 522.235 3-31-87 4116 889 32159 152 522.204 4-03-87 521.909 4-21-87 4116.681 32158.868 521.891 4-23-87 4116.666 32158.854 521.884 4-29-87 4116.714 32158 808 521.879 5-14-87 4116.655 32158.865 521 847 7-22-87 4116655 32158.951 521 834 9-24-87 4116 685 32158 889 521.897 1-12-88 TDR -4078.330 32158.800 -4077.734 32159.356 -4077.769 32159.257 522.700 E.I.* 521.069 3-27-87 520.882 4-03-87 P2E 4164.100 32209.080 515770 E.I." -4164.062 32209.242 515716 3-27-87 4164 088 32209.234 515701 3-31-87 4164.071 32209.209 515.693 4-03-87 516642 4-21-87 4164073 32209.189 515637 4-23-87 4164 067 32209 177 515.632 4-29-87 4164 099 32209 158 515631 5-14 87 4164 065 32209.194 515614 7-22-87 4164073 32209 268 515.620 9-24-87 4164 100 32209 229 515.635 1-12-88 P5E (DOW) P6E (SOW) -4087.080 32163.640 522.640 E.I.* -4086.507 32163.758 521.420 3-27-87 -4086.492 32163.647 521.256 4-03-87 -4086.346 32162982 520.453 4-21-87 -4086.369 32162.940 520.422 4-29-87 -4086.422 32162.877 520.370 5-14-86 -4086.345 32162.928 520.317 7-22-87 -4086.336 32162.996 520.292 9-24-87 -4086.385 32162934 520.281 1-12-88 P3E 4090.960 32166.070 522.560 E.I.* 4090.425 32166.378 521.541 3-27-87 4090.396 32166.345 521.478 3-31-87 4090.367 32166.303 521.443 4-03-87 - 520.812 4-21-87 •4090.163 32165.651 520.778 4-23-87 4090.147 32165.617 520.761 4-29-87 4090.207 32165.569 520.729 5-14-87 4090.130 32165.612 520.683 7-22-87 4090.092 32165.671 520.673 9-24-87 4090.157 32165.617 520.651 1-12-88 P4E -4206470 32235230 515 620 E.I* -4206.353 32235 411 515 627 3-27-87 -4206 368 32235 415 515614 3-31-87 -4206356 32235.397 515610 4-03-87 515577 4-21-87 -4206.367 32235.415 515579 4-23-87 •4206.371 32235.392 515575 4-29-87 4206 383 32235.364 515573 5-14-87 -4206.635 32235451 515391 7-22-87 4206.591 32235.526 515 359 9-24-87 4206.610 32235487 515 400 1-12-88 4256 080 32281.650 513.590 E.I* 4255944 32281 714 513.654 3-27-87 4255.937 32281 720 513642 3-31-87 4255.935 32281 714 513.639 4-03-87 513631 4-21-87 4255943 32281 721 513.629 4-23-87 4255.952 32281 732 513 625 4-29-87 4255.955 32281.697 513625 5-14-87 4255.929 32281 741 513604 7-22-87 4255934 32281 777 513606 9-24-87 4255.973 32281 719 513637 1-12-88 *EI BASELINE DATA FROM ENGINEERS INTERNATIONAL BASED ON 3 SURVEYS 51 COORDINATES FOR THE EAST CLUSTER INSTRUMENTS & MONUMENTS WILLIAMSON COUNTY INSTRUMENT/ MONUMENT NORTHINGS EASTINGS ELEVATIONS DATE M-15 -4124.760 32148 680 522.480 E.I.* -4124.675 32148.789 522.332 3-27-87 -4124.698 32148.781 522.323 3-31-87 -4124.676 32148.746 522.288 521.966 4-03-87 4-21-87 -4124.467 32148.480 521.953 4-23-87 -4124.451 32148.466 521.943 4-29-87 -4124.508 32148.434 521.941 5-14-87 -4124.455 32148.482 521.907 7-22-87 -4124.456 32148.551 521.915 9-24-87 -4124 492 32148.492 521.894 1-12-88 INSTRUMENT/ MONUMENT NORTHINGS EASTINGS ELEVATIONS M-19 DATE ■4125.090 32203.610 518.260 E.I.* 518.109 3-26-87 ■4124.964 32203.542 518.107 3-27-87 •4124.979 32203.535 518.099 3-31-87 ■4124.960 32203.499 518.083 4-03-87 -- 518.008 4-21-87 ■4124.940 32203.428 518.001 4-23-87 -4124.933 32203.427 517.995 4-29-87 -4124.973 32203.389 517.996 5-14-87 -4124.923 32203.440 517.975 7-22-87 -4124.929 32203.516 517.974 9-24-87 -4124.984 32203.460 517.956 1-12-88 M-16 -4111.610 32156.190 522.280 E.I.* 522.018 3-26-87 -4111.324 32156.294 521.988 3-27-87 -4111.331 32156.297 521.975 3-31-87 -4111.303 32156.260 521.941 4-03-87 - 521.560 4-21-87 -4111.028 32155.831 521.547 4-23-87 -4111.013 32155.805 521.539 4-29-87 -4111.071 32155.770 521.535 5-14-87 -4111.028 32155.834 521.505 7-22-87 -4111.010 32155.898 521.510 9-24-87 -4111.085 32155.842 521.487 1-12-88 M-20 ■4125.350 32223.610 515.850 EL* ■4125.248 32223.517 515.731 3-27-87 4125.258 32223.507 515.723 3-31-87 4125.231 32223.482 515.714 4-03-87 515.664 4-21-87 ■4125.238 32223.456 515.659 4-23-87 4125.223 32223.436 515.657 4-29-87 ■4125.274 32223.408 515.656 5-14-87 ■4125.234 32223.464 515.641 7-22-87 ■4125.223 32223.525 515.639 9-24-87 ■4125.283 32223473 515.618 1-12-88 M-17 -4124.930 -4124.761 -4124.781 -4124.628 32163.420 32163.498 32163.430 32163.264 521.850 E.I.* 521.685 3-27-87 521.681 3-31-87 521.632 4-03-87 521.428 4-21-87 M-21 ■4125.490 32243.370 513.570 EL* 513.472 3-26-87 4125.392 32243.298 513.476 3-27-87 4125.414 32243.292 513.465 3-31-87 ■4125.392 32243.268 513.459 4-03-87 - - 513.424 4-21-87 ■4125.413 32243.254 513.419 4-23-87 ■4125.398 32243.247 513.415 4-29-87 ■4125.451 32243.211 513.416 5-14-87 ■4125.412 32243.263 513.402 7-22-87 ■4125.429 32243.332 513.405 9-24-87 ■4125.473 32243.272 513.387 1-12-88 M-18 -4124.820 32183.740 520.380 E.I.* - -- 520.219 3-26-87 -4124.707 32183.734 520.217 3-27-87 -4124.715 32183.732 520.208 3-31-87 -4124.690 32183.700 520.189 4-03-87 - - 520.066 4-21-87 -4124.638 32183.589 520.053 4-23-87 -4124.628 32183.578 520.047 4-29-87 -4124.682 32183.544 520.048 5-14-87 -4124.644 32183.601 520.022 7-22-87 -4124.636 32183.666 520.021 9-24-87 -4124.685 32183 606 520.004 1-12-88 M-22 -4125.800 32263.220 -4125.719 32263.134 -4125.732 32263.112 -4125.701 32263.086 -4125.729 32263.085 -4125.711 32263.083 -4125.766 32263.039 -4125.755 32263.159 -4125.803 32263103 510.430 E.I.* 510.359 3-27-87 510.351 3-31-87 510.345 4-03-87 510.315 4-21-87 510.318 4-23-87 510.312 4-29-87 510.314 5-14-87 7-22-87 510308 9-24-87 510.295 1 12-88 *EI BASELINE DATA FROM ENGINEERS INTERNATIONAL BASED ON 3 SURVEYS 52 COORDINATES FOR THE EAST CLUSTER INSTRUMENTS & MONUMENTS WILLIAMSON COUNTY INSTRUMENT/ MONUMENT NORTHINGS EASTINGS ELEVATIONS M-23 DATE ■4125.860 32283.090 508.130 E.I.* - 508.780 3-26-87 ■4125.791 32283.060 508.081 3-27-87 ■4125.805 32283.038 508.074 3-31-87 ■4125.768 32283.021 508.070 4-03-87 508.052 4-21-87 ■4125.807 32283.014 508.050 4-23-87 ■4125.785 32283.026 508.044 4-29-87 4125.833 32282.977 508.047 5-14-87 ■4125.910 32283 394 508.030 7-22-87 ■4125.826 32283.089 508.030 9-24-87 4125.875 32283.030 508.030 1-12-88 INSTRUMENT/ MONUMENT NORTHINGS EASTINGS ELEVATIONS M-26 DATE 510.800 E.I.* •4126.771 32343.031 510.785 3-27-87 ■4126.771 32343.012 510.779 3-31-87 4126.742 32343.009 510.776 4-03-87 510.779 4-21-87 •4126.788 32343.008 510.771 4-23-87 ■4126.773 32343.031 510.768 4-29-87 ■4126.803 32342.961 510.772 5-14-87 ■4127.337 32343.385 510.763 7-22-87 •4126.825 32343.101 510.766 9-24-87 ■4126.858 32343.005 510.763 1-12-88 M-24 4126.210 32303.030 507.660 E.I.* 4126.142 32302.970 507.632 3-27-87 4126.156 32302.941 507.627 3-31-87 4126.116 32302.939 507.621 4-03-87 -- 507.609 4-21-87 4126.155 32302.934 507 611 4-23-87 ■4126.132 32302.942 507.604 4-29-87 ■4126.183 32302.887 507.608 5-14-87 •4126.412 32303.345 507.592 7-2287 4126.193 32303.051 507.583 9-24-87 ■4126.234 32302 934 507.595 1-12-88 M-27 512.730 E.I* ■4126.782 32363.184 512.735 3-27-87 ■4126.780 32363.176 512.731 3-31-87 -4126.763 32363.163 512.723 4-03-87 512.731 4-21-87 ■4126.807 32363.174 512.724 4-23-87 •4126.795 32363.187 512.720 4-29-87 4126.826 32363 121 512.726 5-14-87 ■4127.502 32363.540 512.709 7-22-87 ■4126.849 32363.252 512.719 9-24-87 ■4126876 32363.172 512.707 1-12-88 M-25 4126 600 32323.100 508.780 EL* 508.750 3-26-87 ■4126 540 32323.042 508.757 3-27-87 4126.532 32323.027 508.752 3-31-87 4126.513 32323.014 508.747 4-03-87 - 508.743 4-21-87 •4126.551 32323019 508.740 4-23-87 4126.538 32323044 508.734 4-29-87 •4126.578 32322.969 508.740 5-14-87 ■4126.963 32323.412 508.728 7-22-87 4126.590 32323.099 508.733 9-24-87 4126.629 32323015 508731 1-12-88 M-28 515.150 E.I.* ■4126.927 32383.636 515.161 3-27-87 -4126.923 32383.611 515.154 3-31-87 •4126.901 32383.601 515.142 4-03-87 515.156 4-21-87 ■4126.940 32383.622 515.155 4-23-87 ■4126.946 32383.632 515.148 4-29-87 ■4126.954 32383.565 515 154 5-14-87 ■4127.804 32383.981 515.137 7-22-87 ■4126.981 32383.697 515.150 9-24-87 -4127.017 32383.613 515.134 1-12-88 *EI BASELINE DATA FROM ENGINEERS INTERNATIONAL BASED ON 3 SURVEYS 53 WILLIAMSON COUNTY BASELINE SURVEY DATA (WEST CLUSTER) AVERAGE INSTRUMENTS NORTHINGS EASTINGS ELEVATIONS NORTHINGS -4400.922 EASTINGS 31327.968 ELEVATIONS MPBX 1 2 3 -4400.931 -4400.979 -4400.855 31327.936 31327.969 31327.998 509.607 509.622 509.609 509.613 TDR 1 2 3 -4401.322 -4401.366 -4401 .242 31337.176 31337.220 31337.245 510.743 510.756 510.744 -4401.310 31337.214 510.748 P7W (SOW) 1 2 3 -4406.115 -4406.161 -4406.033 31306.133 31306.178 31306.189 508.493 508.507 508.495 -4406.103 31306.167 508.498 P6W (DOW) 1 2 3 -4407.305 -4407.356 -4407.221 31301.968 31302.025 31302.044 508.418 508.426 508.419 -4407.294 31302.012 508.421 P1W 1 2 3 -4399.767 -4399.820 -4399.682 31312.301 31312.338 31312.364 508.101 508.117 508.103 -4399.756 31312.334 508.107 P2W 1 2 3 -4404.440 -4404.472 -4404.377 31372.781 31372.824 31372.844 512.574 512.593 512.578 -4404.430 31372.816 512.582 P3W 1 2 3 -4409.067 -4409.094 -4408.985 31432.058 31432.126 31432.151 515.470 515.485 515.470 -4409.049 31432.112 515.475 P4W 1 2 3 -4413.647 -4413.653 -4413.556 31492.212 31492.232 31492.276 518.190 518.204 518.188 -4413.619 31492.240 518.194 P5W 1 2 3 -4419.982 -4420.005 -4419.911 31572.062 31572.086 31572.117 519.580 519.590 519.578 -4419.966 31572.088 519.583 COORDINATES SURVEY DATE: 1 = 4/02/87 2 = 4/22/87 3 = 4/30/87 54 WILLIAMSON COUNTY BASELINE SURVEY DATA (WEST CLUSTER) MONUMENTS NORTHINGS EASTINGS ELEVATIONS NORTHINGS AVERAGE EASTINGS ELEVATIONS M-1 1 -4399.444 -4399.486 31307.801 31307.843 507.581 507.597 -4399.432 31307.836 507.588 2 3 -4399.365 31307.864 507.585 M-2 2 -4412.836 -4412.708 31314.229 31314.258 509.701 509.677 -4412.772 31314.244 509.689 3 M-3 1 -4400.586 -4400.636 31322.597 31322.634 509.351 509.368 -4400.578 31322.631 509.358 2 3 -4400.512 31322.661 509.354 M-4 2 -4402.091 31342.757 511.001 -4402.033 31342.771 510.994 3 -4401.974 31342.784 510.987 M-5 1 -4403.770 -4403.815 31362.201 31362.241 511.844 511.864 -4403.760 31362.239 511.853 2 3 -4403.696 31362.274 511.850 M-6 2 -4405.380 -4405.284 31382.283 31382.306 512.982 512.966 -4405.332 31382.295 512.974 3 M-7 1 -4406.661 -4406.696 31402.282 31402.345 514.455 514.474 -4406.648 31402.334 514.463 2 3 -4406.586 31402.375 514.460 M-8 2 -4408.447 -4408.338 31422.288 31422.324 515.088 515.073 -4408.393 31422.306 515.081 3 M-9 1 -4409.915 31442.169 516.133 -4409.903 31442.216 516.137 2 -4409.951 31442.221 516.147 3 -4409.842 31442.257 516.132 M-10 2 -4411.492 31462.224 517.136 -4411.443 31462.244 517.130 3 -441 1 .394 31462.264 517.123 M-11 1 -4412.930 -4412.943 31482.150 31482.185 517.894 517.908 -4412.906 31482.187 517.899 2 3 -4412.844 31482.226 517.895 M-12 2 -4414.523 31502.067 518.405 -4414.473 31502.090 518.397 3 -4414.422 31502.112 518.389 M-13 1 -4415.991 -4416.019 31522.064 31522.082 518.891 518.906 -4415.976 31522.089 518.896 2 3 -4415.918 31522.121 518.891 M-14 2 -4417.583 -4417.479 31541.930 31541.970 519.178 519.167 -4417.531 31541.950 519.173 3 COORDINATES: 1 = 4-2-87 2 = 4-22-87 3 = 4-30-87 55 WILLIAMSON COUNTY BASELINE SURVEY DATA (WEST CLUSTER) REBAR NORTHINGS EASTINGS ELEVATIONS REBAR NORTHINGS EASTINGS ELEVATIONS R-20 1 : 2 AV -4604.042 -4603.997 -4604.020 31651.354 31651.364 31651.359 525.963 525.967 525.965 R-27 1 2 AV -4409.745 -4409.645 -4409.695 31575.681 31575.722 31575.702 519.237 519.223 519.230 R-21 1 ! 2 AV -4572.285 -4572.227 -4572.256 31637.129 31637.137 31637.133 525.675 525.679 525.677 R-28 1 ! 2 AV -4385.242 -4385.145 -4385.194 31570.481 31570.526 31570.504 518.628 518.611 518.620 R-22 1 ! 2 AV ^539.861 -4539.791 -4539.826 31623.230 31623.255 31623.243 524.889 524.893 524.891 R-29 1 : 2 AV -4360.643 -4360.536 -4360.590 31565.412 31565.460 31565.436 517.325 517.309 517.317 R-23 1 2 AV -4516.929 -4516.860 -4516.895 31613.323 31613.337 31613.330 524.31 1 524.313 524.312 R-30 1 : 2 AV -4336.333 -4336.236 -4336.285 31560.441 31560.491 31560.466 516.985 516.964 516.975 R-24 1 : 2 AV -4494.103 -4494.025 -4494.064 31603.183 31603.208 31603.196 523.396 523.398 523.397 R-31 1 : 2 AV -4312.024 -4311.924 -4311.974 31555.494 31555.546 31555.520 516.979 516.956 516.968 R-25 1 " 2 AV -4471.102 -4471.025 ^471.064 31593.177 31593.205 31593.191 522.382 522.381 522.382 R-32 1 : 2 AV -4288.821 -4288.718 -4288.770 31550.679 31550.731 31550.705 516.650 516.627 516.639 R-26 1 = 2 AV 1 = 2 = -4448.043 -4447.955 -4447.999 4-22-87 4-30-87 31583.407 31583.432 31583.420 521.743 521 .747 521.745 R-33 1 = 2 AV -4263.271 -4263.170 -4263.221 31545.544 31545.607 31545.576 515.807 515.782 515.795 56 APPENDIX D Elevation Changes due to Subsidence WILLIAMSON COUNTY ELEVATIONAL CHANGES DUE TO SUBSIDENCE EAST CLUSTER INSTRUMENTS INSTRUMENT DATE ELEVATION SUBSIDENCE INSTRUMENT DATE ELEVATION SUBSIDENCE (FT) (FT) (FT) (FT) MPBX E.I.* 523.050 521 .226 -1 .824 P1E E.I.* 522.490 522.256 _ 3-27-87 3-27-87 -0.234 4-03-87 521 .098 -1 .952 3-31-87 522.235 -0.255 4-21-87 521 .025 -2.025 4-03-87 522.204 -0.286 4-23-87 520.056 -2.994 4-21-87 521 .909 -0.581 4-29-87 520.01 1 -3.039 4-23-87 521 .891 -0.599 5-14-87 519.990 -3.060 4-29-87 521.884 -0.606 7-22-87 519.937 -3.113 5-14-87 521 .879 -0.61 1 9-24-87 519.926 -3.124 7-22-87 521 .847 -0.643 1-12-88 519.887 -3.163 9-24-87 521 .834 -0.656 1-12-88 521 .897 -0.593 TDR E.I.* 522.700 521 .069 -1 .631 P2E E.I.* 515.770 515.716 - 3-27-87 3-27-87 -0.054 3-31-87 520.951 -1 .749 3-31-87 515.701 -0.069 4-03-87 520.882 -1.818 4-03-87 515.693 -0.077 4-21 -87 515.642 -0.128 4-23-87 515.637 -0.133 4-29-87 515.632 -0.138 5-14-87 515.631 -0.139 7-22-87 515.614 -0.156 9-24-87 515.620 -0.150 1-12-88 515.635 -0.135 P5E (DOW) E.I.* 522.640 521 .420 -1.220 P3E E.I.* 3-27-87 515.620 51 5.627 - 3-27-87 0.007 3-31-87 521 .323 -1.317 3-31-87 515.614 -0.006 4-03-87 521 .256 -1.384 4-03-87 515.610 -0.010 4-21 -87 520.453 -2.187 4-21-87 515.577 -0.043 4-29-87 520.422 -2.218 4-23-87 515.579 -0.041 5-14-87 520.370 -2.270 4-29-87 515.575 -0.045 7-22-87 520.317 -2.323 5-14-87 515.573 -0.047 9-24-87 520.292 -2.348 7-22-87 515.391 -0.229 1-12-88 520.281 -2.359 9-24-87 515.359 -0.261 1-12-88 515.400 -0.220 P6E (SOW) E.I.* 522.560 521 .541 -1.019 P4E E.I.* 513.590 513.654 - 3-27-87 3-27-87 0.064 3-31-87 521 .478 -1.082 3-31-87 513.642 0.052 4-03-87 521 .443 -1.117 4-03-87 513.639 0.049 4-21-87 520.778 -1 .782 4-21-87 513.631 0.041 4-29-87 520.761 -1 .799 4-23-87 513.629 0.039 5-14-87 520.729 -1.831 4-29-87 513.625 0.035 7-22-87 520.683 -1.877 5-14-87 513.625 0.035 9-24-87 520.673 -1 .887 7-22-87 513.606 0.016 1-12-88 520.651 -1.909 9-24-87 513.606 0.016 1-12-88 513.637 0.047 *EI BASELINE DATA FROM ENGINEERS INTERNATIONAL BASED ON 3 SURVEYS 57 WILLIAMSON COUNTY ELEVATIONAL CHANGES DUE TO SUBSIDENCE EAST CLUSTER MONUMENTS MONUMENT DATE ELEVATION SUBSIDENCE MONUMENT DATE ELEVATION SUBSIDENCE (FT) (FT) (FT) (FT) M-15 E.I.* 522.480 522.332 -0.148 M-19 E.I.* 518.260 518.107 ._ 3-27-87 3-27-87 -0.153 3-31-87 522.323 -0.157 3-31-87 518.099 -0.161 4-03-87 522.288 -0.192 4-03-87 518.083 -0.177 4-21-87 521 .966 -0.514 4-21-87 518.008 -0.252 4-23-87 521 .953 -0.527 4-23-87 518.001 -0.259 4-29-87 521 .943 -0.537 4-29-87 517.995 -0.265 5-14-87 521.941 -0.539 5-14-87 517.996 -0.264 7-22-87 521.907 -0.573 7-22-87 517.975 -0.285 9-24-87 521.915 -0.565 9-24-87 517.974 -0.286 1-12-87 521 .894 -0.586 1-12-88 517.956 -0.304 M-16 E.I.* 522.280 521 .988 -0.292 M-20 E.I.* 515.850 515.731 „ 3-27-87 3-27-87 -0.119 3-31-87 521 .975 -0.305 3-31-87 515.723 -0.127 4-03-87 521 .941 -0.339 4-03-87 515.714 -0.136 4-21-87 521 .560 -0.720 4-21-87 515.664 -0.186 4-23-87 521 .547 -0.733 4-23-87 515.659 -0.191 4-29-87 521 .539 -0.741 4-29-87 515.657 -0.193 5-14-87 521 .535 -0.745 5-14-87 515.656 -0.194 7-22-87 521 .505 -0.775 7-22-87 515.641 -0.209 9-24-87 521.510 -0.770 9-24-87 515.639 -0.21 1 1-12-87 521 .487 -0.793 1-12-88 515.618 M-17 EI* 521 .850 521 .685 -0.165 M-21 E.I.* 513.570 513.476 .. 3-27-87 3-27-87 -0.094 3-31-87 521 .681 -0.169 3-31-87 513.465 -0.105 4-03-87 521 .632 -0.218 4-03-87 513.459 -0.111 4-21-87 521 .428 -0.422 4-21-87 4-23-87 4-29-87 5-14-87 7-22-87 9-24-87 1-12-88 513.424 513.419 513.415 513.416 513.402 513.405 513.387 -0.146 -0.151 -0.155 -0.154 -0.168 -0.165 M-18 E.I.* 520.380 520.217 -0.163 M-22 E.I.* 510.430 510.359 .. 3-27-87 3-27-87 -0.071 3-31-87 520.208 -0.172 3-31-87 510.351 -0.079 4-03-87 520.189 -0.191 4-03-87 510.345 -0.085 4-21-87 520.066 -0.314 4-21-87 510.315 -0.115 4-23-87 520.053 -0.327 4-23-87 510.318 -0.112 4-29-87 520.047 -0.333 4-29-87 510.312 -0.118 5-14-87 520.048 -0.332 5-14-87 510.314 -0.116 7-22-87 520.022 -0.358 9-24-87 510.308 -0.122 9-24-87 520.021 -0.359 1-12-88 510.295 -0.135 1-12-88 520.004 -0.376 *EI BASELINE DATA FROM ENGINEERS INTERNATIONAL BASED ON 3 SURVEYS 58 WILLIAMSON COUNTY ELEVATIONAL CHANGES DUE TO SUBSIDENCE EAST CLUSTER MONUMENTS MONUMENT DATE ELEVATION SUBSIDENCE MONUMENT DATE ELEVATION SUBSIDENCE (FT) (FT) (FT) (FT) M-23 E.I.* 3-27-87 508.130 508.081 -0.049 M-26 E.I.* 3-27-87 510.800 510.785 „ -0.015 3-31-87 508.074 -0.056 3-31-87 510.779 -0.021 4-03-87 508.070 -0.060 4-03-87 510.776 -0.024 4-21-87 508.052 -0.078 4-21-87 510.779 -0.021 4-23-87 508.050 -0.080 4-23-87 510.771 -0.029 4-29-87 508.044 -0.086 4-29-87 510.768 -0.032 5-14-87 508.047 -0.083 5-14-87 510.772 -0.028 7-22-87 508.030 -0.100 7-22-87 510.763 -0.037 9-24-87 508.030 -0.100 9-24-87 510.766 -0.034 1-12-88 508.030 -0.100 1-12-88 510.763 -0 037 M-24 E.I.* 507.660 507.632 -0.028 M-27 E.I.* 512.730 512.735 3-27-87 3-27-87 0.005 3-31-87 507.627 -0.033 3-31-87 512.731 0.001 4-03-87 507.621 -0.039 4-03-87 512.723 -0.007 4-21-87 507.609 -0.051 4-21-87 512.731 0.001 4-23-87 507.611 -0.049 4-23-87 512.724 -0.006 4-29-87 507.604 -0.056 4-29-87 512.720 -0010 5-14-87 507.608 -0.052 5-14-87 512.726 -0.004 7-22-87 507.592 -0.068 7-22-87 512.709 -0.021 9-24-87 507.583 -0.077 9-24-87 512.719 -0.011 1-12-88 507.595 -0.065 1-12-88 512.707 -0.023 M-25 EL* 508.780 508.757 -0.023 M-28 E.I.* 515 150 515.161 .. 3-27-87 3-27-87 0.011 3-31-87 508.752 -0.028 3-31-87 515.154 0004 4-03-87 508.747 -0.033 4-03-87 515.142 -0.008 4-21-87 508.743 -0.037 4-21-87 515.156 0.006 4-23-87 508.740 -0.040 4-23-87 515.155 0.005 4-29-87 508.734 -0.046 4-29-87 515.148 -0.002 5-14-87 508.740 -0.040 5-14-87 515.154 0.004 7-22-87 508.728 -0.052 7-22-87- 515.137 -0.013 9-24-87 508.733 -0.047 9-24-87 515.150 0000 1-12-88 508.731 -0.049 1-12-88 515.134 -0.016 *EI BASELINE DATA FROM ENGINEERS INTERNATIONAL BASED ON 3 SURVEYS 59 WILLIAMSON COUNTY ELEVATION CHANGES DUE TO SUBSIDENCE (WEST CLUSTER INSTRUMENTS) INSTRUMENT DATE ELEVATION CHANGE ED £D_ MPBX TDR P7W (SOW) P6W (DOW) BASE 509.613 — 5-1 3-87 509.616 0.003 7-23-87 509.601 -0.012 BASE 510.748 5-1 3-87 510.748 0.000 7-23-87 510.729 -0.019 BASE 508.498 5-1 3-87 508.501 0.003 7-23-87 508.461 -0.037 BASE 508.421 5-1 3-87 508.424 0.003 7-23-87 508.384 -0.037 INSTRUMENT DATE ELEVATION CHANGE (FT) (FT) P1W BASE 5-13-87 508.107 508.106 -0.001 7-23-87 508.069 -0.038 P2W BASE 512.582 5-13-87 512.577 -0.005 7-23-87 512.534 -0.048 P3W BASE 5-1 3-87 515.475 51 5.472 — -0.003 7-23-87 51 5.455 -0.020 P4W BASE 5-1 3-87 518.194 518.188 — -0.006 7-23-87 518.161 -0.033 P5W BASE 519.583 — 5-13-87 519.564 -0.019 7-23-87 51 9.568 -0.015 60 WILLIAMSON COUNTY ELEVATION CHANGES DUE TO SUBSIDENCE (WEST CLUSTER MONUMENTS) MONUMENT DATE ELEVATION CHANGE MONUMENT DATE ELEVATION CHANGE (FT) (FT) (FT) (FT) M-1 BASE 507.588 M-8 BASE 515.081 5-1 3-87 507.593 0.005 5-1 3-87 515.075 -0.006 7-23-87 507.574 -0.014 7-23-87 51 5.058 -0.023 M-2 BASE 5-1 3-87 509.689 509.697 0.008 M-9 BASE 5-1 3-87 516.137 516.134 — -0.003 7-23-87 509.675 -0.014 7-23-87 516.120 -0.017 M-3 BASE 509.358 — M-10 BASE 517.130 5-13-87 509.362 0.004 5-13-87 517.124 -0.006 7-23-87 509.340 -0.018 7-23-87 517.107 -0.023 M-4 BASE 510.994 M-11 BASE 517.899 5-13-87 510.991 -0.003 5-1 3-87 517.893 -0.006 7-23-87 510.976 -0.018 7-23-87 517.874 -0.025 M-5 BASE 511.853 M-1 2 BASE 518.397 — 5-1 3-87 51 1 .855 0.002 5-1 3-87 51 8.388 -0.009 7-23-87 51 1 .838 -0.015 7-23-87 51 8.362 -0.035 M-6 BASE 512.974 ... M-1 3 BASE 518.896 — 5-1 3-87 512.969 -0.005 5-1 3-87 518.889 -0.007 7-23-87 512.953 -0.021 7-23-87 518.862 -0.034 M-7 BASE 5-1 3-87 514.463 514.460 -0.003 M-1 4 BASE 5-1 3-87 519.173 519.158 — -0.015 7-23-87 514.441 -0.022 7-23-87 519.150 -0.023 61 WILLIAMSON COUNTY ELEVATION CHANGES DUE TO SUBSIDENCE (WEST CLUSTER INSTRUMENTS) REBAR DATE ELEVATION CHANGE REBAR DATE ELEVATION CHANGE (FT) (FT) (FT) (FT) R-20 BASE 525.965 R-27 BASE 519.230 5-13-87 525.968 0.003 5-13-87 519.196 -0.034 7-23-87 " 7-23-87 9-25-87 519.192 519.193 -0.038 -0.037 R-21 BASE 525.677 — R-28 BASE 518.620 ... 5-13-87 525.678 0.001 5-1 3-87 518.580 -0.040 7-23-87 525.669 -0.008 7-23-87 9-25-87 518.578 518.579 -0.042 -0.041 R-22 BASE 5-13-87 524.891 524.890 -0.001 R-29 BASE 5-1 3-87 517.312 517.266 — -0.046 7-23-87 ___ ... 7-23-87 9-25-87 517.251 517.251 -0.061 -0.061 R-23 BASE 524.312 R-30 BASE 516.975 ... 5-13-87 524.312 0.000 5-1 3-87 516.915 -0.060 7-23-87 524.289 -0.023 7-23-87 9-25-87 516.901 516.912 -0.074 -0.063 R-24 BASE 523.397 R-31 BASE 516.968 — 5-13-87 523.395 -0.002 5-1 3-87 516.889 -0.079 7-23-87 ... — . 7-23-87 9-25-87 516.866 516.871 -0.102 -0.097 R-25 BASE 522.382 R-32 BASE 516.639 — 5-13-87 522.379 -0.003 5-1 3-87 516.538 -0.101 7-23-87 522.356 -0.026 7-23-87 9-25-87 516.524 516.526 -0.115 -0.113 R-26 BASE 5-1 3-87 521 .745 521 .739 -0.006 R-33 BASE 5-1 3-87 515.795 515.680 — -0.115 7-23-87 521 .704 -0.041 7-23-87 9-25-87 515.657 515.666 -0.138 -0.129 62 APPENDIX E Water Level Readings and Precipitation Data ILLINOIS MINE SUBSIDENCE RESEARCH PROGRAM WILLIAMSON COUNTY SITE PIEZOMETERS IN THE EAST INSTRUMENT CLUSTER WATER LEVEL READINGS GLACIAL DRIFT WELLS BEDROCK WELLS WELL DESIGNATION ConE P1E P2E P3E P4E P5E (DOW) P6E (SOW) TOP OF WELL ELEVATION (FT) 535.54 522.49 515.77 515.62 513.59 522.56 512.00 WELL DEPTH (FT) 17.25 32.50 16.45 17.00 21.85 165.00 99.80 YEAR DATE TIME DEPTH TO WATER LEVEL (FT) 1986 July 31 11.40 28.20 DRY DRY 12.20 28.50 21.80 Sept 9 12.85 28.00 15.80 DRY 12.40 29.60 21.50 Sept 12 14.00 28.70 DRY DRY 13.70 30.30 22.40 Sept 20 12.95 28.05 15.80 16.15 12.45 29.90 21.60 Oct 3 13.10 28.00 15.85 16.15 12.40 30.00 21.55 Nov 20 14.20 28.80 DRY DRY 13.85 31.60 22.65 Dec 11 ... 28.75 DRY DRY 13.65 31.75 22.40 1987 Feb 2 12.20 28.70 DRY DRY 13.30 31.90 21.90 Mar 23 10.29 25.10 DRY 16.60 11.85 36.00 26.64 Mar 24 ... ... ... ... ... 36.15 26.69 "SUBSIDENCE EVEr JT" Mar 26 10.31 31.37 DRY DRY 12.30 28.00 * 70.35* Mar 27 12:30 10.44 28.42 DRY DRY 12.25 28.00 * 70.35* 4:30 10.43 28.54 DRY DRY 28.00 * 70.35* Mar 30 5:20 ... 29.89 DRY DRY 12.45 " Apr 1 11:00 10.28 29.82 DRY DRY 12.26 "" Apr 2 11:50 10.39 30.10 DRY DRY 12.42 " Apr 3 11:10 ... 30.15 DRY DRY 12.54 11 3:30 ... 30.10 DRY DRY 12.50 " Apr 16 8:30 9.78 DRY DRY 16.64 12.33 " Apr 21 3:00 9.49 DRY DRY DRY 12.27 40.00* Apr 23 11:30 9.60 DRY DRY DRY 12.25 » Apr 29 2:00 9.90 DRY DRY DRY 12.28 ■ May 14 11.44 DRY DRY DRY 13.07 » May 27 12.12 DRY DRY DRY 13.55 11 July 22 15.57 DRY DRY DRY 14.65 " Sept 24 16.32 DRY DRY DRY 16.28 11 1988 Jan 12 16.50 DRY DRY DRY 17.52 " May 16 14.55 DRY DRY DRY 15.70 " Oct 11 ... DRY DRY DRY 16.55 " 1989 Dec 6 17 DRY DRY DRY 14.5 11 * Denotes well is blocked and dry at this depth. 63 ILLINOIS MINE SUBSIDENCE RESEARCH PROGRAM WILLIAMSON COUNTY SITE WATER LEVEL ELEVATIONS (EAST INSTRUMENT CLUSTER) GLACIAL DRIFT WELLS BEDROCK WELLS WELL DESIGNATION ConE P1E P2E P3E P4E P5E (DOW) P6E (SOW) WELL DEPTH (FT) 17.25 32.50 16.45 17.00 21.85 165.00 99.80 YEAR DATE WATER LEVEL ELEVATIONS (FT) 1986 July 31 524.14 494.29 d-499.32 d-498.62 501 .45 494.06 500.84 Sept 9 522.69 494.49 499.97 d-498.62 501.25 492.96 501.14 Sept 12 521.54 493.79 d-499.32 d-498.62 499.95 492.26 500.24 Sept 20 522.59 494.44 499.97 499.47 501.20 492.66 501.04 Oct 3 522.44 494.49 499.92 499.47 501.25 492.56 501.09 Nov 20 521.34 493.69 d-499.32 d-498.62 499.80 490.96 499.99 Dec 11 ... 493.74 d-499.32 d-498.62 500.00 490.81 500.24 1987 Feb 2 523.34 493.79 d^199.32 d-498.62 500.35 490.66 500.74 Mar 23 525.25 497.39 d-499.32 499.02 501.80 486.56 496.00 Mar 24 — — ■SUBSIDENCE EVENT" — — — Mar 26 525.23 — ... ... ... ... ... Mar 27 525.10 493.84 d-499.27 d-498.63 501.40 *493.54 M51.07 Mar 27 525.11 493.72 d-499.27 d-498.63 ... • Mar 31 ... 492.35 d-499.25 d-498.61 501.19 ■ Apr 1 525.26 492.42 d-499.25 d-498.61 501.38 " Apr 2 525.15 492.14 d-499.25 d-498.61 501.22 < Apr 3 ... 492.05 d-499.24 d-498.61 501.10 " Apr 3 ... 492.10 d-499.24 d-498.61 501.14 " Apr 16 525.76 489.70 d-499.19 498.97 501.31 " Apr 21 526.05 d-489.41 d-499.19 d-498.58 501.36 *480.45 Apr 23 525.94 d-489.39 d-499.19 d-498.58 501.38 • Apr 29 525.64 d-489.38 d-499.18 d-498.58 501.35 • May 14 524.10 d-489.38 d-499.18 d-498.57 500.56 • May 27 523.42 d-489.38 d-499.18 d-498.57 500.08 " July 22 519.97 d-489.35 d-499.16 d-498.57 498.98 ■ Sept 24 519.22 d-489.33 d-498.91 d-498.34 497.33 " 1988 Jan 12 519.04 d-489.33 d-498.91 d-498.34 496.09 ■ May 16 520.99 d-489.33 d-498.91 d-498.34 497.91 ■ 1989 Dec 6 — d-489.33 d-498.91 d-498.34 497.06 " d- Denotes well is dry * Denotes well is blocked and dry at this elevation 64 ILLINOIS MINE SUBSIDENCE RESEARCH PROGRAM WILLIAMSON COUNTY SITE PIEZOMETERS IN THE WEST INSTRUMENT CLUSTER GLACIAL DRIFT WELLS BEDROCK WELLS WELL DESIGNATION ConW P1W P2W P3W P4W P5W P6W (DOW) P7W (SOW) TOP OF WELL ELEVATION (FT) 536.59 508.11 512.58 515.48 518.19 519.58 508.39 508.45 WELL DEPTH (FT) 28.90 29.55 16.25 49.80 14.95 30.50 203.10 100.00 YEAR DATE TIME DEPTH TO WATER LEVEL (FT) 1986 July 31 19.00 10.40 13.20 13.70 14.65 15.40 38.20 17.65 Sept 9 18.75 11.60 14.55 15.00 14.35 16.50 36.55 19.15 Sept 12 19.50 11.80 15.75 15.45 DRY 17.50 37.10 19.50 Sept 20 19.00 11.65 15.30 15.25 14.25 16.85 36.55 19.00 Oct 3 18.83 11.42 15.40 15.30 14.30 17.00 36.81 18.50 Nov 20 20.50 11.55 DRY 16.10 DRY 18.30 37.95 17.75 Dec 11 20.90 11.25 DRY 15.90 DRY 18.10 37.75 17.25 1987 Feb 3 21.05 11.10 15.25 14.90 DRY 17.67 37.97 16.20 Apr 1 20.47 9.65 13.15 13.27 12.19 15.73 40.45 16.05 Apr 15 20.05 9.41 12.23 12.87 10.55 15.30 43.45 18.12 Apr 22 20.10 9.25 11.31 12.28 12.30 15.01 43.40 18.98 Apr 30 20.00 9.72 12.41 13.31 13.51 15.14 45.60 22.67 May 13 20.13 10.36 13.11 14.77 14.88 16.15 45.49 23.65 May 28 20.25 11.12 13.78 15.82 DRY 16.64 46.78 24.08 July 22 20.75 12.98 DRY 17.87 DRY 17.98 50.95 23.88 Sept 24 21.76 15.86 DRY 20.19 DRY 20.24 54.65 29.58 1988 Jan 13 23.50 16.45 DRY 22.10 DRY 22.43 60.07 22.00 May 16 22.61 13.24 DRY 18.10 DRY 19.30 63.32 18.81 Oct 6 23.22 18.15 15.62 22.62 DRY 22.97 65 ILLINOIS MINE SUBSIDENCE RESEARCH PROGRAM WILLIAMSON COUNTY SITE WATER LEVEL ELEVATIONS (WEST INSTRUMENT CLUSTER) GLACIAL DRIFT WELLS BEDROCK WELL DESIGNATION ConW 28.90 P1W 29.55 P2W 16.25 P3W 49.80 P4W 14.95 P5W 30.50 P6W (DOW) 203.10 P7W (SOW) 100.00 WELL DEPTH (FT) YEAR DATE WATER LEVEL ELEVATIONS (FT) 1986 July 31 517.59 497.71 499.38 501.78 503.54 504.18 470.19 490.80 Sept 9 517.84 496.51 498.03 500.48 503.84 503.08 471.84 489.30 Sept 12 517.09 496.31 496.83 500.03 d-503.24 502.08 471.29 488.95 Sept 20 517.59 496.46 497.28 500.23 503.94 502.73 471.84 489.45 Oct 3 517.76 496.69 497.18 500.18 503.89 502.58 471.58 489.95 Nov 20 516.09 496.56 d-496.33 499.38 d-503.24 501.28 470.44 490.70 Dec 11 515.69 496.86 d-496 33 499.58 d-503.24 501.48 470.64 491.20 1987 Feb 3 515.54 497.01 497.33 500.58 d-503.24 501.91 470.42 492.25 Apr 1 516.12 498.46 499.43 502.21 506.00 503.85 467.94 492.40 Apr 15 516.54 498.70 500.35 502.61 507.64 504.28 464.94 490.33 Apr 22 516.49 498.86 501.27 503.20 505.89 504.57 464.99 489.47 Apr 30 516.59 498.39 500.17 502.17 504.68 504.44 462.79 485.78 May 13 516.46 497.75 499.47 500.71 503.31 503.43 462.90 484.80 May 28 516.34 496.99 498.80 499.66 DRY 502.94 461.61 484.37 July 22 515.84 495.13 DRY 497.61 DRY 501.60 457.44 484.57 Sept 24 514.83 492.25 DRY 495.29 DRY 499.34 453.74 478.87 1988 Jan 13 513.09 491.66 DRY 493.38 DRY 497.15 448.32 486.45 May 16 513.98 494.87 DRY 497.38 DRY 500.28 445.07 489.64 Oct 6 513.98 489.96 496.96 492.86 DRY 496.61 66 ILLINOIS MINE SUBSIDENCE RESEARCH PROGRAM WILLIAMSON COUNTY SITE *** PRECIPITATION DATA FROM MARION STATION*** TOTAL AND DEPARTURE FROM NORMAL PRECIPITATION FROM JUL 1 986 - DEC 1 988 *** FOR GRAPHING: DEPARTURE FROM NORM VS. MONTH *** DEPARTURE YEAR MONTH FROM NORM *NOAA TOTAL (in) (in) 1986 JUL 2.35 5.96 AUG 3.26 6.76 SEP 1.29 4.34 OCT 1.04 3.23 NOV -1.51 2.13 DEC -0.53 2.78 1987 JAN -1.69 1.11 FEB 0.65 3.72 MAR -1.99 2.73 APR -2.04 2.06 MAY -2.18 1.81 JUN -0.23 3.57 JUL 2.05 5.66 AUG -1.58 1.92 SEP -1.71 1.34 OCT -0.67 1.52 NOV 0.88 4.52 DEC 2.90 6.21 1988 JAN -1.31 1.49 FEB -0.39 2.68 MAR 0.49 5.21 APR -2.14 1.96 MAY -1.64 2.35 JUN -2.62 1.18 JUL 2.83 6.44 AUG -1.94 1.56 SEP 0.80 3.85 OCT 0.91 3.10 NOV 3.70 7.34 DEC -0.13 3.18 67