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1 IV. GEOTECHNICAL DATA COLLECTION SUMMARY 4.01 General During 1998, no special detailed geotechnical data collection was necessary for either localized failure areas or highwalls excavated at slope angles steeper than default slope angles. General observations were made in the active mining areas in the Central Quarry and in the North Quarry, but no detailed data collection was required or performed for interim slopes there, in accordance with permit conditions. Geologic mapping of new final highwalls was performed at Bench 2 and Bench 1 highwalls of t the east side of the Central Quarry. In addi[ion, the optical survey of surface survey monitor points in and around the repaired failure area in the east side of the Central Quarry continued in 1998. ' i 19 8 Dur ng 9 , excavation in the Central and the North Quarries did not exceed any conditions that would require reevaluation of stability of the cut slopes. Mining in the Central Quarry was limited to excavation of benches at least 40 fr wide and highwalls 40 ft high or less at the ' south end, and to the planned bench configuration (50 fr to 60 ft wide benches and 40 fr high highwalls), or flatter, on the east side. Within the North Quarry, the 1998 highwalls and benches did not exceed an overall slope configuration of 1H:1V. CAMAS and Haley & ' Aldrich have continued occasional observations of the temporary slopes in these areas although evaluations and reporting of slope stability and geotechnical data for temporary slopes of this configuration are not specifically required by conditions of the approved permit amendments. ' 4.02 East Side of the Central Quarry ' A. Geologic Mapping Geologic mapping da[a was collected for Bench 2 and Bench I at the eas[ side of the Central Quarry. Joint orientation (strike and dip) data was measured at approximately 100 ft intervals or areas of structural interest for final highwall segments established during 1998. Other mapping data and observations such as fault shear zone locations, fold axis trends, and intrusive dike locations, as well as notes about rock type and condition, were documented. This information is included on the topographic map included as Plate 1 in Appendix A. B. Optical Survey CAMAS provided survey support of the investigation and repair of the localized ' failure in the east side during 1996. Survey support continued during 1998 in the form of continued monitoring of the post-repair surface settlement points via optical survey. Survey data for March 1997, May 1997, March 1998, and October of 1998 ' document the performance of the repair during 1997. A discussion of these data is provided in Section 5.02, and the data are included as Appendix B. ' G:~PROIECTSC0.00 Mormm~ Quarry\009Amual Report Ga¢cMlGy AEEeMUm\1998\98ryi muYup.doc Page 5