The Influence Of Wall Thickness Of Large Diameter Circular Diaphragm Wall On The Horizontal Displacement Of Foundation Pit

Reducing the deformation of retaining structure has important significance for the stable and secure of foundation pit and surrounding facilities. the factors of impacting deformation of retaining structure have been studied by many scholars. By the study of the factors which impact on the deformation of the wall thickness of the retaining structure, the following conclusions were got. Increasing the thickness of the wall can effectively reduce the horizontal displacement of the foundation pit. Continuing to increase the thickness of the wall, when the thickness exceeds a certain value, the horizontal displacement of foundation pit cannot be significantly reduced. This conclusion can help determine the trends of the foundation pit of horizontal displacement changes when the thickness of the wall change, but cannot determine the reasonable range of thickness of the wall, so the study of the relationship between the wall thickness and the horizontal displacement of the foundation pit is still important.Circular diaphragm wall have obviously spatial effects. It can use its own advantages of arch effect, which helps reduce foundation pit deformation, to change the external pressure of soil and water into tangential pressure of retaining structure. With the projects which have deep-big foundation pit or have high requirements on environmental protection arise. Circular diaphragm wall is widely used in excavation engineering. In this paper, taking large diameter diaphragm wall as an object, plane and space finite element model of circular diaphragm walls which have or not have ring BEAM were established, by using ANSYS software pre-processing module. Use methods of plane spring-BEAM and3D spring-slab to calculate the horizontal displacement of the wall, when the wall is subject to different thickness.By calculating and analyzing the actual project, get the conclusion that increasing the thickness of the wall can effectively reduce the horizontal displacement of the foundation pit. Continuing to increase the thickness of the wall, when the thickness exceeds a certain value, the horizontal displacement can’t be significantly reduced. Further analysis of the results, the functional relations of wall thickness-maximum horizontal displacement and wall thickness-the rate of decrease of displacement were got. It could provide some reference for designers when they think over thickness of the wall at the process of design.