Structure And Parameters Analysis Of Bridge Abutment In Soft Clay

The phenomenon, such as piles failure, abutment rupture, road surface behind abutment appearing settlement in succession for a long time after construction, are common damage of the abutment which constructed on the soft clay, and which have influenced the normal running of the traffic seriously. Its reason is because the bearing capacity of the soft clay is very low, and has very obvious rheological characteristics. The already existing balance state of the soft soil layer will be destroyed by the unsymmetrical and vertically additional loads which caused by the construction of the retained fill behind the abutment and the transportation of the vehicle, and thus results in great visco-plastic deformation in the soft clay. It will induce great extrusion load on the piles of the abutment. Analysis and study on the analytical method of the abutment which constructed on the soft clay has been performed in this paper.Firstly, on the basis of the forerunners' research and local inspection, analysis the fundamental mechanic character of the abutment constructed on soft clay overall, and point out that how to consider the influence to the abutment construction caused by the existence of soft soil layer is the key point to the mechanic analysis of the abutment constructed on the soil clay. It establishes the groundwork in theory for setting up finite element calculation model.Secondly, on the basis of summarizing and analyzing the rheological characteristics of the soft clay based on theory of the model, the suitable conditions of the theoretical formula to calculate the additional lateral load on piles under abutment caused by the lateral movement of the soft soil has been analyzed. Set up a simplified finite beam element calculation model, and prove the exactness of calculating model by comparing to the results of the centrifuge test. Then point out the reason of the disease of the abutment constructed on the soft clay through an analysis of project instance.Finally, the factors which influence the mechanic character of the abutment in the design has been analyzed by utilizing the simplified calculation model, therefore has got some helpful conclusions.