Study Of The Interaction Effect On Pile-anchor Structure With Earth Berms Which In The Foundation Pit

Soil mass retention technique is put to more and more extensive application in foundation excavation in recent years. Soil mass retention is a foundation pit excavation technique whereby the central soil mass is removed while the peripheral soil mass near the foundation pit wall is retained until the center excavation proceeds to the bottom and the underground structure has been constructed to the design level and matured to the desired strength. The retained soil mass before the support structure is then removed in stages. There are a lot of researches and discussions on foundation pit soil mass retention in both foreign and domestic research and engineering communities.But so far we can not reasonably determine the effect about this method, which reduce the implantation in the actual project.Therefore, to carry out the research about the effect of this method has important engineering practice and theoretical significance.This article first use ABAQUS establish a calculation model about pile-bolt bracing structure when the soil is reserved, reveals the effect of mechanical characters about soil mass retention to pile-bolt bracing structure, and on this basis, further discusses influence of geometry parameters, infers the calculation method about pile-bolt bracing structure force-deformation when the soil is reserved. The main work includes the following several aspects.(1) Using ABAQUS establish three-dimensional finite element model of pile-bolt bracing structure, soil mass retention is set in the dynamic simulation of excavation process, reveals the effect of mechanical characters about soil mass retention to pile-bolt bracing structure by the contrast of the influence between limited reserve soil and semi-infinite soil;(2) Analysis the influence law about geometrical parameters(width, height and slope) changes of limited reserve pit soil, By comparing the degree of influence on the parameters of soil reserved geometrical analysis, discussing the optimization design, giving optimum geometry;(3) According to the mechanical characteristics of pile-bolt bracing structure when the soil is reserved, basing on simplified elastic resistance method and three-parameter winker elastic foundation beam model, inferring the response differential equations of pile-bolt bracing structure. Through the pile discrete and matrix transfer method, giving the semi-analytical answer about supporting piles force response.And compared with the numerical results, the feasibility of the theoretical calculation method is tested;(4) We draw the conclusion that the pile-anchor supporting structure before the reserved soil can as part of the supporting structure, working with the pile-bolt bracing structure and jointly maintaining the stability of the foundation through theoretical analysis and numerical simulation;...