Analysis Of Mechanical Charactersitics And Influence Factors On Bearing Capacity Of Multi-Element Composite Foundation

With the great application and economic values, the multi-element composite foundation is developed and applied more than ever. Much more experiment researches and engineering tests were carried on and a few reference design theory and compute methods were gained. The bearing capacity and mechanical characteristics of the multi-element foundation were influenced by pile and soil and the interaction between them as well, which are related with the type of the pile, engineering features of the soil, construction technology and the arrangement form of the pile etc. However, as a new foundation disposal technology, the study of mechanism and theory were still in preliminary state and many problems are in want of resolve.First, the commonly used method of the existing foundation bearing capacity and settlement of the multi-element composite foundation are summarized. Considering the difference between the practical bearing capacity of the pile in multi-element composite foundation and the limited bearing capacity of the singe pile, the correction coefficient was offered. The computation method of the multi-element composite foundation step by step was modified and a new modified compute method was presented.Second, the constitute model of the soil and the boundary conditions were analyzed. Considering the elasto-plastic features of the soil and the non-linear characteristics of the contact between pile and soil, the non-linear model was constructed with the help of the FLAC3D program. The system was presented for evaluating the mechanical features and the bearing capacity of the multi-element composite foundation.Finally, the load transferring characteristics of the pile in the multi-element composite foundation was analyzed as well as the additional stress. The stress and settlement of the pile and soil under the action of the vertical load were discussed. The influence by the parameters such as pile length, the pile space and the diameters of the pile was also researched.