The Combined Action Analysis Of Composite Pile Foundation

The design of pile-balsa foundation, in a long time, has been carried on according to routine pile foundation' design due to have no efficient computing method. The carrying capacity of soil can't get fully used. The distance between routine piles foundation is oversized in order to use soil's supporting capacity and think over the pile-soil's combined supporting capacity. This pile foundation is called composite pile foundation. Now the mechanics of composite foundation is not very clear, this article is mainly on composite foundation combined action.First, this article use the theoretical t-z curve to simulate the single pile's working status, compared with the elastic method, the layered soil's property can be better thought over. The result of value analysis shows this method can simulate the single pile's p-s curve well. On the base of single pile's analysis, the single pile's settlement is computed under the burden of adjacent pile, and give the interactive factor a ' s change with different load and distance between piles.In the analysis of balsa, Kirchhoff's thin plate theory is important. With the buildings are getting higher, the thickness of balsa is getting more thick too and the shape is getting irregular. To this type balsa, if rectangle thin plate element is sill used will has limitation. So this article use arbitrary quadrilateral thick and thin balsa universal element.And then, Using the ANSYS program and predigesting the pile-balsa foundation to plane strain problem, some main parameters(foundation stiffness, pile soil module ratio, replacement ratio, etc) were calculated to analyze the influence to stress field and deformation field in soil.Afterwards, this simplified spatial program is worked out on the base of this article's theory, and analyzed some main parameter's influence. Some regular conclusion is gotten.At last, a example was calculated using this article's program, and compared with the actual measurement result. Some useful results are gotten, and can be used into practice.