The Research And Analysis On Deformation Of Large Underground Engineering By Top-down Method On Weak Soil Area

By the steady and fast development of national economy, continuously expansion ofurban construction, advance of construction level, the civil air defenses works will serve asthe bridge for coordinate economic construction into connect the urban construction, the mostas the unprecedented development of air-raid shelters.Under the background of one large-scale air-raid shelters in Dongguan, analysis anddiscuss deformation of the structure, which is one air-raid shelters on weak soil by using thetop-down construction method.First. Give the detail introduction on the theory of top-down construction method, pressflows, the technical feature and so on, which is used on underground construction.Second. Introduce the most using model of foundation, and the theory of top-downconstruction method, finite element analysis of floor.Third. Now we use load analysis on top-down construction during which is building,conclude that this method can reduce the deformation of underground diaphragm wall, theyawing force which bears by the plant. Using SAP2000and the P-S load-settle curves toanalysis a sample model, which used the top-down construction method, to find the influenceof internal force in floor which produced by differential settlement.Fourth Analysis the construction phase and usage phase of raft foundation, which used thetop-down construction method, find that if there are some weak soil under it, in order toreduce the differential settlement and come-up, we can increase the stiffness of base plate.Now use the equivalent static loading method and nonlinear time-history method to have adynamic analysis on independe civil air defence works, then conclude the feature anddifference between them.