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我队81、82两年承担晋中盆地地下水长观建网勘察，完成钻探工作量8000余米，计29个孔（孔组），部分钻孔在第四纪古河道、冲积扇和洪积扇地层施工，卵砾石粒径大，松散、层厚。其中有四个钻孔，全孔均为卵砾石、漂石。卵石直径小的30—50毫米，大的漂石直径0.4—0.8米，从孔内可以取出圆柱状完整岩心（见附图）。卵砾石层中夹有粗细砂层。有的还夹有薄层粘土。厚层卵砾石地层钻进乃目前工艺技术上的难题，主要特点是地层胶结性差，孔壁极不稳
81,82 years of our team to assume Jinzhong basin groundwater long view of network construction survey, the completion of the drilling workload of 8,000 meters, accounting for 29 holes (hole group), part of the ancient drilling in Quaternary alluvial fans and alluvial Fan stratum construction, gravel large diameter, loose, layer thickness. Among them, there are four holes, all holes are gravel, boulders. Small pebbles 30-50 mm in diameter, large boulders 0.4-0.8 m in diameter, can be taken from the hole cylindrical integrity of the core (see photo). Gravel layer sand and sand layer sandwiched between. Some also have a thin layer of clay. Thick pebble stratum drilling is the current technology problems, the main feature is the formation of poor cementing, pore wall is very unstable