Study On Deep Pit Foundation Engineering Deformation And Supporting Interaction

With the rapid development of national economy and city construction, the foundation pit engineering technology level in Our country have greatly increased, At the same time there emerged many problems while we design and construction the deep foundation pit, such as the theory of supporting structure design is not perfect and there exist many shortcomings in the traditional calculation method, In addition, foundation pit engineering is one subject that rely on regional strongly, Different parts of the engineering geological condition is very different, the aspects mentioned above will bring a lot of difficulties in deep foundation pit engineering design and construction.In this paper we will as the main line of the design of foundation pit supporting structure and deformation control. Expounds the commonly used supporting structure types in foundation pit engineering design and construction, and the key points of deep foundation pit engineering design and the calculation method of the soil pressure on the retaining wall and supporting structure internal force. Introducing the form of foundation pit deformation and deformation of the calculation and deformation control standard and reduce the deformation of the main measures. Combined with a foundation pit engineering in shaoxing city, Introduces the purpose and mission of foundation pit engineering monitoring, and the method of foundation pit monitoring technology and principle. Finally, with the aid of large finite element software PLAXIS simulate the initial geostress state of the foundation pit before excavation and step-by-step excavation and supporting the whole process, and analyzes the deformation of the foundation pit under different retaining piles stiffness, different support stiffness and different soil parameters, getting the influence law of foundation pit deformation under different supporting condition:(1) the retaining piles maximum horizontal displacement occurred in near the bottom of foundation pit, in a certain range increasing the stiffness of the retaining piles can effectively reduce the retaining piles maximum horizontal displacement, but the top and the bottom of the pile of displacement were also will increase;(2) increase the stiffness of the interior support, the retaining piles pile top displacement and the maximum horizontal displacement will reduced;(3) under different soil parameters, increase the elastic modulus of soil excavation, the biggest retaining piles horizontal displacement and pile top and the bottom of the pile displacement will increase;during this the change of the pile top displacement is not obvious, the maximum horizontal displacement and the pile bottom displacement change significantly, along with the increase of soil modulus, the maximum bending moment value will reduce. Through the research in this paper, Hope of foundation pit engineering design and construction of how to choose reasonable supporting structure type, control the deformation of foundation pit, prevent the failure of the supporting structure, reduce the foundation pit engineering accident of some reference value.