| At present, pile-raft foundation is widely applied in both the tall and super high-rise buildings. At the same time, the research on the bearing capacity of pile-raft foundation is well paid attention in the geotechnical engineering areas. The fruits on theory calculation, experimental analysis and engineering practices are in abundance by the researchers at home and abroad. But some unreasonable phenomenons often happen due to lack of profound researches, which are improved.Basing on the former fruits, the work of this paper concentrated on the mechanism of pile-soil-raft interaction and the numerical analysis. The work contains: Explain the numerical analysis principle on the bearing capacity of the pile-raft foundation; The structural and model program are designed, which is called Program for Pile -Raft Foundation Numerical A nalysis, abbreviated to PPRFNA; The analysis and comparison on the bearing capacity of the four-pile-raft foundation considering no interaction and interaction are carried on basing the various pile spans. The problems about the relationship between load and settlement; the effect coefficient of pile group; the characters in soil settlement field and stress field; the loading transfer capability of piles; the load sharing behavior of piles and soil are discussed. These analysis and comparison come to some conclusions.The conclusion on the bearing capacity of pile-raft foundation in this paper reflects some regulations in pile-soil-raft interaction, which include of the relationship between load and settlement; the effect coefficient of pile group; the characters in soil settlement field and stress field; the loading transfer capability of piles and the load sharing behavior of piles and soil. The conclusion of this paper will provide guiding basis for experimental researches and engineering practices. Of course, these conclusions need necessarily be validated by the farther practices and theories.In addition, PPRFNA owns the universal and general format of numerical analysis program mainly for static problems and mimesis static problems on geotechnical engineering. PPRFNA can be applicable to given problem by adding elements and foundation models and improving algorithm. It is practicable and valuable. |
