Research On Dig And Support Of Foundation Pit Of Dongzhimen Station Of City Railway In Beijing

Dongzhimen station of city railway № 13 in Beijing is a single layer undergroundstation and the terminus of the city railway № 13. The station lies in outside ofDongzhimen and the north-east corner of road crossing of Dongerhuan Road andDongzhimen Street. It tends toward south-north. The total construction area of the station is16269.6 ㎡. The construction method to the main framework adopted directly diggingfoundation pit. The stratum of the deep foundation belongs to the unsaturated soil. The pit is160.2m in length from south to north, 72.5m in width from east to west and 16.10m in depth.This thesis carries out the research work focusing on dig and support of deep foundation pit inthe unsaturated soil.The first content of the thesis is researching the case of deep foundation pit in Beijingregion , analyzing the material of construction monitoring which is compared with the resultof academic calculate. The achievement is the factual earth pressure is consumedly less thanthe result of calculate by technical specification in the region of unsaturated soil whenexcavating the deep foundation pit. The design for deep foundation pit of the nowadaysspecification is conservative. The design for the support of foundation may depend on theeffect on the displacement of surroundings around foundation pit.The second content of the thesis is comparing the date of construction monitoring withthe result of academic calculate of deep foundation pit basing on the theory of the unsaturatedsoil, probing into the selected value of earth pressure when designing the support of deepfoundation pit in Beijing region, bringing forward a new method. The research on earthpressure of deep foundation pit in Dongzhimen station indicates that the generic Rankineearth pressure is resultful and may be generalized to calculate the earth pressure of theunsaturated soil in Beijing region step by step and the biggish error can be avoided betweenthe factual measured value and the classical theoretical value in the region of unsaturated soilin Beijing. The soil potential may be exerted fully. Economy may be increased.