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<br />rock that is generally angular sand and gravel size material. Widely fractured granitic rock is <br />exposed in the benches and high walls of the reclaimed pit. <br />The northeast wall of the Houchin Gravel Pit currently slopes at about a 3:1 down to <br />the southwest toward Highway 24. The pit bottom varies in width from about 80 feet on the <br />southeast to 140 feet on the northwest. The stripped topsoil from the pit is stockpiled to the <br />east of the mining limits. We understand the pit has been excavated using bulldozer and <br />front-end loader excavation equipment. The material exposed in the Houchin Gravel Pit <br />generally consists of decomposed granitic rock that is primarily sand and gravel-size similar <br />to the upper 2:1 slope portion of the adjacent reclaimed pit. Small areas of granitic rock with <br />closely spaced fractures were exposed in the lower portion of the pit. The bulldozer being <br />used to excavate the pit was having difficulty in the areas of exposed granitic rock, and <br />either a more powerful bulldozer or blasting will likely be required for excavation in these <br />areas. <br />The high walls for the adjacent pit were constructed using a drill, blast and excavate <br />sequence. The benches were left to flatten the overall slope angle and to act as intermediate <br />catch points for any falling rock. <br />Conclusions <br />We believe it may be possible to reclaim the Houchin Gravel Pit using a similar high <br />wall and bench technique provided similar hard bedrock is encountered in the eastern and <br />northeastern cut slopes of the pit. We recommend excavating the pit from the upper limits of <br />the pit downward at a 2:1 (horizontal to vertical) slope until hard rock is encountered. The <br />hard rock should then be exposed for observation of the fractures so that appropriate high <br />walls and benches can be designed. Excavation of the high walls will likely involve drilling <br />and blasting to loosen and reduce the size of the material. The 2:1 slope should include <br />periodic cross ditches to control surface water flows and reduce erosion. <br />If hard bedrock is not encountered in the excavation of the east and northeast sides of <br />the pit, the resulting 2:1 pit slope would be stable. The 2:1 cut slopes to in the reclaimed pit <br />to the northwest and along Highway 24 are in similar materials and have been re-vegetated <br />successfully. <br />Limitations <br />The conditions observed in the adjacent pit are representative of conditions observed <br />in the pit at the exposed locations only. Variations in the subsoil conditions not indicated by <br />our observation are possible. We recommend a representative of our office observe the <br />completed excavations to assist in design of the final pit slope reclamation configurations. <br />We believe this investigation was conducted with that level of skill and care ordinarily <br />used by geotechnical engineers practicing in this area at this time. No warranty, express or <br />implied, is made. We should evaluate the rock for the design of the high wall and benches <br />HOUCHIN, INC. 2 <br />HOUCHIIN GRAVEL PIT <br />PROJECT NO. CS75483.145-R1 <br />5:10516000-064891CS76483.00011gS2. Reports\0515663-145-R1.tloe <br />