江西城门山铜矿采矿工业场地工程地质影响评价

Engineering geological impact assessment of mining industrial site construction of Chengmenshan Copper Mine

江西城门山铜矿拟新建采矿工业场地位于露天采场东侧,地貌类型为剥蚀低丘,场地地层复杂,各岩土层性状差异和地层变化较大,稳定性一般。由于场地(破碎站)的动荷载对地基稳定性影响较大,考虑采用第4-3层中风化石灰岩层作为拟建场地基础持力层,场地岩土施工应考虑支护稳定性和地下水对施工的影响。场地基坑预计开挖深度为11 m,根据周边情况,边坡采用混凝土喷面的支护体系。地下水可引起第3-1层花岗岩残积土软化崩解、第4-2层灰岩残积土土体液化,深基坑开挖时应特别注意这两层土体和基坑支护稳定性问题。

The proposed site is located on the east side of the open pit and has a denudation mound topography and geomorphology.The site has complex stratum of rock and soil with significant differences and changes,resulting in average stability.Considering that the large dynamic load of the site(crushing station)has a great influence on the foundation stability,it is recommended to utilize the weathered lime rock layer in the 4th and 3rd layers as the foundation bearing layer of the proposed site.The excavation depth of the foundation pit is expected to be 11 m.According to the actual surrounding situation,the slope will be supported using a concrete spraying surface supporting system.The stability of support and the influence of groundwater on construction should be considered during geotechnical construction.Groundwater can cause softening and disintegration of the granite residual soil in the 3-1 layer,as well as liquefaction of the limestone residual soil in the 4-2 layer.Therefore,special attention should be paid to the stability these the two layers of soil and the stability of the foundation pit support during deep excavation.