The Experimental Research Of Configuration Of Pile Foundation Effect On Its Settlement

Because of the poor geological condition in the coastal soft area, the bearing capacity of the foundation soil is lower, which will cause large settlement of buildings. In this situation, compared the theoretical calculation with general theory, the actual sedimentation value is different, sometimes even has very big disparity.Generally speaking, there are two aspects of problem about settlement or differential settlement of foundation. One is the deformation mechanism of foundation soil and anther one is the influence to upper structure when the settlement or differential settlement occurs. Foundation is under the surface of the ground and the differential settlement of it may cause a lot of damages to the structure above including excessive deformation, cracking, leaning and collapse. Therefore, it is necessary to find a way to control the differential settlement.This paper is mainly aimed at the first problem using the long-short-pile foundation to control and levelling the differential settlement so that makes uniformsettlement to the foundation.In the design using long-short-pile foundation, the foundation settlement and settlement discrepancy can be reduced by adjusting the length of the piles in different position, which can improve the foundation bearing capacity. Compared the pile, the long-short-pile has lower rigidity and higher adhension, which can effectively absorb seismic wave energy so that to form a response control structure. In the process of the foundation soil improvement, the on-site soil is available to mix with cement and steel slag so that the construction is simple and earth moving is reduced, which can achieve a good economic benefits and environmental effect.This paper focused on the model tests of long-short-pile composite foundation, which is part of Liaoning natural science fund project"differential settlement control and application of steel slag in the foundation treatment". Firstly, we sloved the selection of model's similitude ratio, design of model trough and force transmissive frame, selection of raft and model pile, and distribution and installation method of piles. Secondly, we operated model test and analyzed the results of the experiments. This laboratory experiments proved the feasibility that the differential settlement can be effectively controled by this kind of composite foundation through adjusting the length of the piles in different position.