The Numerical Simulation Analysis Of Ring Beam Retaining System Of Large Foundation Pit

With the social development,the useble urban space is reducing, numbers of engineering problems emerge as the exploiting and using scale of underground space is ceaseless grandness:how to control the deformation of the deep foundation pit effectively; how to provide more space at a limited construction yard as much as possible; how to solve the problem of the difficulty of large-scale foundation pit supporting; how to layout founditon pit retaining system to make it used efficiently and economically; For this temporary structure, how to design it to make it reasonable, safe and reliable. These are problems which needed to study and solve, ring beam retaining system-a new type of foundation pit retaining structures, emerged in the face of such difficulties, and demonstrated its enormous superiority in the area of foundation pit retaining.Ring beam surporting system uses the arch effect of annular structure,will transforme the force into axial pressure mainly and give full play to the good load performance of concrete structure,because of its characteristics of enough stiffness and small deformation,it can save materials while control foundation pit deformation effectively. moreover, ring beam retaining system formed a large space in the internal of loop pillared,easy to construct and shortening construction period.This paper describes various commonly used type of foundation pit surporting structure in current engineering firstly, put forward the ring beam retaining system, which is superior in internal bracing, and analyse the structure characteristic of ring beam retaining system, induction and analysis of its arrangement form. This paper suggest that we can use the ring beam retaining system, which can fully exert its structure and geometrical characteristic, for large-area and anomalistic foundation pit. And we can set some truss support system surround it to meet the requirement of our project.Secondly,the paper has done analysis about the theory of foundation pit surporting,and researched the distinctness among the various calculation methods of foundation pit surporting. The paper proposed the methord of elastic foundation beam and the method of plates on elastic foundation are the reasonable calculation methods of foundation pit surporting and it should get the direction to engineering design.Thirdly, the paper has introduced the calculation methods of surporting system.The plane finite element and whole three-dimensional finite element methord can be used to analysis,moreover,analysis and summary about the finite element method is made base on ANSYS.And finally, according to the structure characteristic of ring beam retaining system, this paper choose two methods (the methord of elastic foundation beam combined with the methord of finite element calculation of plane supporting structure, and the method of plates on elastic foundation) to calculate the ring beam retaining system and gets fine mutual verification. Then,finite element numerical simulation anlysis is made to two different ring beam retaining system, compare the calculated results and analyse the structure characteristic and performance of them, summarizes conclusions and make some reasonable suggestions for project design of deep foundation pit.