Study On The Modified Dependent Pressure Method In Foundation Pit Analysis

Three methods are in common use in the analysis of deep foundation pit, such as the classical method, the elastic fulcrum method, finite element method, etc., and the Chinese foundation pit standard specifies the elastic fulrum method as the specified method. But the methods above have some limitations. Therefore, this dissertation proposes a new method called DPM. The main content of this dissertation is as follows:(1) The dissertation summarizes the reaearch status and existing problems of the three methods mentioned above:the classical method can’t analyze the deformation of the structure, and it can’t consider the influence of the dynamic construction progress; the assumption of the elastic fulcrum method in geotechnicl material properties is not reasonable, so as the soil pressure distribution and its size; the determination of the cconstitutive model and the calculation parameters are difficlut for using the finite element method.(2) Based on the Chinese foundation pit standard, the basic principle of the elastic fulcrum method is intrudued, and the problems of the method are also summarized. Then the dissertation puts fordord the new method that can solve the problems of the elastic fulcrum method.(3) The DPM assumes that the geotechnical material is of elastoplastic; when the foundation pit is in no excavation, the pressure effecting on the structure is static earth pressure; during the dynamic construction progress, the earth pressure is between active earth pressure and passive earth pressure; the method can consider the mutual affection between the soil and the structure.(4) The dissertation selects cantilever structure, anchor-reinforced structure and support structure, using the DPM and he elastic fulcrum method to analysze the deformation of the sturucture and the horizontal displacement. Compared the analysis results of the new method with the actual monitoring data, the dissertation demonstrates the rationality of the modified method.(5) The finite element analysis software GEO5 is used to carry out the finite element analysis of the anchor pull structure. The results are compared with the DPM and the and further demonstrate the rationality of the DPM.(6) The DPM is applied to a subway project which is reinforced by steel pile and anchor. The analysis results show that the project is safety, reasonable and economic...