Nonlinear Analysis Of Retaining Structure For Deep Foundation

In absence of matured code's guidance, the deep foundation is in the stage of practice and exploration. So the research for intensifying calculated and numerical methods and im- proving the rationality in guiding engineering of deep foundation is important. As temporary structure, the elastic designed methods are often used for retaining structure of deep structure and measured stress is smaller compared to the designed value, therefore optimized design, simulating the basic process and considering plasticity of retaining structure have important theory meaning and practicality.The objective of this paper is putting forward the plastic method in view of economics and practicality, and then applying to the engineering.In this paper, the present status of development and the sorting of the deep foundation engineering is introduced. This paper combines specific practice of retaining structure. It mostly studies on the content of interaction between soil and retaining structure by means of utilizing theory analysis, numerical simulation, on-the-spot monitor in real time etc. It researches the relevant contents about retaining structure displacement, retaining structure stress change etc of deep foundation, and has obtained some achievements.This paper analyzes interaction mechanism between soil and retaining structure during enclosed excavation in deep foundation by using theory according to the phenomenon of measured stress being smaller than the designed value in retaining structure of deep foundation. It has demonstrated that the present designed methods of retaining structure are conservative. It also put forward the concept of plasticity about retaining structure under low horizontal displacement and environmental limits.By analyzed the method of the pole system FEM and the entity FEM, it indicates the later method is more reasonable, and also putting forward the predigested method of earth pressure under excavation surface.In order to describe the peculiar change and development rule of displacement field and force field under special state,ANSYS program is used to carry on the numerical simulation to retaining structure. By comparing the results of numerical simulation with the designed and measured value, it proved the feasibility considering about plasticity of retaining structure.