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1 <br /> <br /> <br /> <br />1 <br /> <br /> <br /> <br />1 <br />1 <br />1 <br />1 <br />1 <br /> <br />1 <br />t <br /> <br /> <br />IV. GEOTECHNICAL DATA COLLECTION SUMMARY <br />4.01 General <br />During 2000, detailed geotechnical data collection was necessary for highwalls excavated at <br />slope angles steeper than default slope angles in the Central Quarry. During 2000, <br />excavation in the Central Quarry exceeded the default slope configuration of IH:1 V due to <br />the modified mine plan presented in Technical Revision No. 3. As required by the <br />Amendments, detailed geotechnical data collection was necessary for these highwalls. Since <br />final highwalls were complete, data from these highwalls was collected and used to reevaluate <br />these steeper slopes. <br />During 2000, excavation in the North Quarry did not exceed any conditions that would <br />require reevaluation of stability of the cut slopes. General observations were made in the <br />active mining areas in the North Quarry, but no detailed data collection was required or <br />performed for interim slopes there, in accordance with permit conditions. <br />Geologic mapping of new final highwalls was performed in the Central Quarry and in the <br />North Quarry. The strike and dip of structural features was measured with a Brunton <br />compass (using a 14°E magnetic declination) and recorded using "right hand rule" convention <br />(bearing of strike direction with dip direction being 90° to the right). In addition, the optical <br />survey of surface survey monitor points in and around the repaired failure area in the east <br />side of the Central Quarry continued in 2000. <br />4.02 Central Quarry <br />Geologic mapping data was collected for Bench B, C, and D of the Central Quarry. Joint <br />orientation data was measured at accessible areas and areas of structural interest for final <br />highwall segments established during 2000. Other mapping data and observations such as <br />fault/shear zone locations, fold axis trends, and intrusive dike locations, as well as notes <br />about rock type and condition, were documented. This information is shown on Figure 1. <br />Aggregate Industries provided survey support of the investigation and repair of the failure in <br />the east side during 1996. Survey support continued during 2000 in the form of continued <br />monitoring of the post-repair surface settlement points via optical survey. Survey data for <br />March 1997, May 1997, March 1998, October 1998, August 1999, and August 2000 <br />document the performance of the repair during 1997. A discussion of these data is provided <br />in Section 5.02, and the data are included as Appendix A. <br />4.03 North Quarry <br />Geologic mapping data was collected for Benches 4, 5, 6, 7, and 8 at the north and west sides <br />of the North Quarry. Joint orientation data was measured at approximately 100 ft intervals <br />and/or areas of structural interest for final highwall segments established during 2000. Other <br />mapping data and observations such as fault/shear zone locations, fold axis trends, and <br />intrusive dike locations, as well as notes about rock type and condition, were documented. <br />This information is shown on Figure 2. <br />' GAPROJECf5~2(1200 Mornson Quarry~W812(M10trepon~_'000 geo¢chmcal addendum.da 4 <br />