Optimization Design Of Composite Foundation Of Rigid-long-pile & Flexible-short-pile

With the rapid development of the technique of ground treatment, the application of composite foundation is more extensive. And concerning the advantages of security and economy etc, although the Long-short-pile composite foundation is a new technique of reinforcing foundation, it will be applied extensively. However, some problems are still exist in the design of this composite foundation, so some more researches needs to be done.Firstly, combined with an engineering example, the deformation and cost of the rigid-long-pile & flexible-short-pile composite foundation and the whole-long-pile composite foundation under the same geological condition have been calculated and compared.Secondly, with the finite element software ANSYS, some factors affecting the deformation of rigid-long-pile & flexible-short-pile composite foundation such as the form of pile plane layout,the number,modulus,and length of long (short) pile,the modulus of soil,the thickness and modulus of cushion and the strength of base are analysed ; And their effects to the whole performance of the composite foundation are also discussed in this paper, then a range of reasonable results of the above parameters, as the basis of the optimization design about control settlement of the rigid-long-pile & flexible-short-pile composite foundation in practical projects, are summarized according to the calculated results.