Soil Arching Effect Of Closed Diaphragm Wall As Bridge Foundation

As a new type of bridge foundation, closed diaphragm wall has been widely used in domestic for its high stiffness, good bearing capacity and good economic benefits. In this paper, the bearing capacity of closed diaphragm wall and the soil arching effect of soil in the area below foundation are studied by the methods of numerical simulation. The main studied contents and corresponding results are as follows:(1) The classification and application of closed diaphragm wall are described in this paper. And the development of the study of soil arching effect is analyzed.(2) The bearing capacity of closed diaphragm wall foundation under vertical loading is simulated in this paper. The results show that it will not failure under vertical loading. The limit bearing capacity of this foundation is mainly controlled by desired settlement.(3) The effect of soil properties to the settlement of closed diaphragm wall foundation and soil arching effect is also studied by changing the value of elastic modulus, cohesion, internal friction angle and density of soil used in the numerical models. The results show that the better of the physical properties of soil, the smaller of the settlement of closed diaphragm wall foundation and the more obvious of soil arching effect. Thereinto, we find that the effect of elastic modulus is maximum, and the effect of density is smallest.(4) The influence of the width and height of wall body to the ultimate bearing capacity of closed diaphragm wall foundation and soil arching effect is studied. The results show that the wider of the wall, the better of the ultimate bearing capacity of closed diaphragm wall foundation. But, if the value of the width of wall body is too large or small, the exertion of soil arching effect will be limited. An appropriate width can enhance the action of soil arching effect. The influence of the height of wall body to the ultimate bearing capacity of closed diaphragm wall foundation and the effect of soil arching at the end of the soil core is minor.