Particle Flow Simulation Of Foundation Pit Rataining Pile

With the accelerated process of urbanization, in recent years, the bulk of the deep foundation pit are emerging,relate to pile-soil interaction problem of deep foundation pit is complicated.According to the causal relationship between the pile-soil interaction excavation,piles are divided into active pile and passive pile.For example, a large area of preloading when excavating fountion pit and other construction projects causes lateral displacement of soil, we call the pile as "passive piles." The piles under direct horizontal load, or direct lateral displacement are "active pile." Based on the relevant reports and studies, this paper uses two-dimensional granular flow software PFC2D to talk about stress on pile due to soil lateral displacement and the pile itself directly moving at a certain speed.First of all, it mainly analyses pile response of section plane at a certain depth to soil lateral displacement which is passive pile, mainly discusses the pile load - load wall displacement curve,the soil arching effect ultimate load, soil arch height and effect of pile spacing,as well as compare the square pile and circular pile under the same conditions, at last it concludes reasonable pile spacing and performance of square pile is better than the circular pile.Then, this paper simulates pile under the direct horizontal displacement, which includes horizontal section and vertical profiles of the pit.Studies finds that similar to the passive pile of soil arching effect, soil arch is also formed in the passive zone of the soil, load on pile distributes to a wider range of soil behind pile through the arch. At the same time, the extent of soil arch on different stages and the soil arch ultimate load values with different spacing are compared. Also this paper analyzes displacement direction changes and stress changes in soil in and outside pit during the excavation and movement of pile.Finally, it makes comprehensive about all contents,points out some problems existing in particle flow simulation and prospects the future.