2002-04-12_PERMIT FILE - M2002052 (26)

Home Browse Search

Geotechnical Engineering Report Gravel Evaluation - Saddlehorn Ranch Site NE of Highways 257 and 60 -Milliken, Colorado Terracon Project No. 21015136 Terracon were drilled within the area of the proposed gravel pit as directed by the client. The test borings augment borings previously drilled at the site by The Andesite Company. All borings drilled by Terracon were advanced with atruck-mounted drilling rig utilizing 4-inch diameter solid stem augers. The borings were located in the field by the client. Ground surface elevations at each boring location were interpolated from the topographic map prepared by Acklam & Associates, Inc Dated August 29, 2001. The accuracy of boring locations and elevations should only be assumed to the level implied by the methods used to determine each. Lithologic logs of each boring were recorded by the field engineer during the drilling operations. At selected intervals, samples of the subsurface materials were taken from auger cuttings and by driving split-spoon samplers. Penetration resistance measurements were obtained by driving the split-spoon samplers into the subsurface materials with a 140-pound hammer falling 30 inches. The penetration resistance value is a useful index in estimating the consistency, relative density or hardness of the materials encountered. Groundwater conditions were evaluated in each boring at the time of site exploration, and 1 day after completion of drilling. Laboratory Testing All samples retrieved during the field exploration were returned to the laboratory for observation by the project geotechnical engineer and were classified in accordance with the Unified Soil Classification System described in Appendix C. Samples of bedrock were classified in accordance with the general notes for Bedrock Classification. At that time, the field descriptions were confirmed or modified as necessary and an applicable laboratory testing program was formulated to determine engineering properties of the subsurface materials. Boring logs were prepared and are presented in Appendix A. Laboratory tests were conducted on selected soil and bedrock samples and are presented on the boring logs and in Appendix B. The test results were used for the gravel evaluation, development of. All laboratory tests were performed in general accordance with the applicable local or other accepted standards. Selected soil and bedrock samples were tested for the following engineering properties: Water Content • Grain size 2