The Analysis Of Nonlinear Interaction Of Piles-soil-raft Considering Soil Consolidation

With the development of the theory of interaction and the progress of computer technology, the cognition of piles-raft foundation has reached a new standard. But in the present research of pile-soil-raft interaction, due to the complicacy of pile-raft foundation, the factor of soil consolidation is still not considered yet. However, soil consolidation has important effectiveness to the system of pile-soil-raft interaction, it has significant value in theory and practice to consider the factor of soil consolidation when we study the mechanism of interaction. The purpose of this project is to probe the working character of non-linear interaction of pile-soil-raft considering consolidation and develop the theory of dual control of composite pile foundation.According to the traits of FLM, semi-numeric and semi-analytic, the Symbolic Math Toolbox of MATLAB is used to deduce the formula of FLM. The deducing procedure shows that it is very convenient to get the analytic solution while facing the complicated geotechnical problem.Based on the accomplished research, the following methods in this dissertation is adopted: Biot Consolidation Finite Layer Method (BCFLM) is used to analyze the pile-soil-raft interaction system which takes soil consolidation into account. Raft is regarded as rigid body, the interaction of piles, soil and excess pore pressure is simulated by BCFLM, and load transfer function is used to simulate the pile in non-liner working situation.According to these analytical methods, the corresponding numerical computing program, Consolidation Pile Raft interaction (CPRI), with advanced language C++ is accomplished. Different situations, single-pile raft, four-pile raft and nine-pile raft, are calculated with CPRI. With the computing results, the variation of the raft settlement, pile counterforce, soil counterforce and pore pressure at different time are analyzed, which agree with the general rule and show the contribution of soil consolidation on the interaction. At the same time, the contrast program PRI (Pile Raft Interaction), according to the interaction theory without soil consolidation, has been programmed too. The results of CPRI agree with that of PRI when time is long enough, which indicates that the method of pile-soil-raft interaction considering soil consolidation is correct.The analysis of non-linear pile-soil-raft interaction considering soil consolidation is attempted at first time in this dissertation, which makes contribution to the realization of the principles of the non-linear interaction and establishes the foundation for the further research.