Research On Nonliner Element Free Method And Its Applying In Mechanic Analysis Of Pile Group Under Inclined Loads

With the fast development of large span bridge and high-rise buildings, the analysis and design principle of pile group under inclined loads has been become a problem to be solved in civil engineering. According to the current codes, piles under inclined loads top are analyzed respectively under axial and lateral loads with the results superposed, in which inaccurate error is inevitable. Focusing on this point, the analysis of pile and pile group under inclined loads are thoroughly discussed in this article. Thus, combining with the engineering characteristics of pile group under inclined loads and working in the element free method reflecting the complex boundary conditions, deep research for mechanic analysis of pile group under inclined loads had been doing.Firstly, the fundamental theories of Moving Least Squares Method (MLSM) which is the mathematical basis of EFM are studied thoroughly; then, combining with the mold of practical pile group, the solving method for the elastic-plastic nonlinear problems had been established, detailed research is conducted on some key problems, such as the selection of weighted function, the selection of influence radius of nodes, the solving method for the complexity of boundary. Moreover, by making use of the hybid iterative algorithm i.e. incremental initial stress method in the EFM program of pile group, an EFM program was developed which could do linear elastic analysis, elastic-plastic analysis for pile group by using the EFM program mentioned.Secondly, by using the EFM for analysis of inclined loads of pile group, applying in mechanic analysis of pile group under inclined loads had been stressly studied in details. Variation characteristics of internal force & deformation and the failure modes of pile group under inclined loads were researched by the EFM analysis of singlerow pile group of high bearing platform and low bearing platform. Furthermore, a mass of numerical calculations of the internal force of pile group under different magnitude and obliquity loads is made by the program. Based on the obtained results, a series of qualitative conclusions are drawn which can be applied to guide engineering practice.