Inclined Loads The Non-linear Finite Element Analysis Of Pile Groups Under The Internal Force

With the fast development of large span bridge and high-rise buildings, the bearing capacity and the length of piles are increasing, and the analysis and design principle of piles 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.Firstly, the development and application of piles is summarized, behavior of piles under inclined loads are discussed, and a summarization of existent computational methods is made in this article. Secondly, considering the complexity of the analysis of inclined-loading pile, nonlinear finite element method is adopted to calculate the internal force and displacement of pile group under inclined loads, with the concept of equivalent width presented to simplify 3D problems into 2D problems. And a program is developed as well, which is able to consider the continuity, elastic-plasticity and layered characteristic of soil around the pile shaft.Besides, the interactions among pile, base slab and soil are considered in this program and contact surface element is used to simulate slipping and crazing between pile and soil, or between base slab and soil under loads. Then, the non-tension analysis is proposed, to reflect the low-tensile property of soil and concrete. 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.