Abstract:The anti-floating anchor bolt is an important technique to control groundwater buoyancy in construction works. The anti-floating anchor bolt project for the underground square foundation pit in north Xingyuhuafu in Qingdao was taken as the research object. The preliminary design was carried out based on the existing anti-floating anchor design theory, and the numerical simulation test was carried out using FLAC3D. The stress and deformation of the foundation pit floor under the combined action of structural loads, underground water buoyancy and anchor bolts were analyzed. The optimization scheme for anti-floating anchor bolts was obtained through trade off of the loading conditions and construction cost.

Abstract:Dashen CP302 is the first deep slim hole under-balanced casing window sidetracking horizontal well which is independently designed and constructed in Daqing oilfield, and has concentrated all the technical characteristics and the difficulties of deep well, slim hole well, under-balanced well, casing window and horizontal well. By optimization on the technical scheme, whipstock with duplex milling and cone milling window is determined. The paper introduces casing sidetracking technology and well trajectory control technology in detail.

Abstract:According to the deformation in a deep foundation pit excavation process, analysis was made on the basic cause of engineering foundation pit deformation; the reasonable optimizations were timely implemented on the original design scheme with effective limits to the deformation of foundation pit with the safety ensuring on surrounding buildings of the foundation pit, cost saving, convenient construction and short construction period.