深基坑开挖对临近桩基建筑物变形影响分析

THREE-DIMENSIONAL FINITE ELEMENT ANALYSIS OF THE INFLUENCE OF DEEP FOUNDATION PIT EXCAVATION ON ADJACENT BUILDINGS

为了探索地铁深基坑开挖对不同区域内建筑物桩基础的内力和变形影响,本文基于杭州地铁八号线工程实例,采用基于小应变土体硬化模型(HSS模型)的三维有限元分析方法研究了深基坑开挖对桩身位移、桩身沉降、桩身弯矩、地表沉降和承台倾斜角度的影响,并与工程实测进行了比较。研究表明:开挖对临近建筑桩身侧移、桩身弯矩、地表沉降、承台倾斜角的影响范围是二倍的基坑开挖深度,地表沉降呈现两种不同的模式,承台倾斜角在距离基坑一倍开挖深度远处最大。

It is of great significance for guiding engineering practice to analyze the internal force characteristics of the pile foundation adjacent to excavation during construction and to explore the deformation law of the pile foundation of buildings in different areas.Based on the concrete engineering example of the foundation pit of the Wenqiao section of Hangzhou Metro Line 8,this paper analyzes the influence of deep foundation pit excavation of the subway to the adjacent building pile foundation by the three-dimensional finite element analysis method based on the small strain soil hardening model(HSS model).The simulation results were compared with the engineering measurement results in terms of the pile displacement,pile settlement,pile bending moment,ground settlement,and pile cap inclination angle of pile foundation at different distance between foundation pit and building.The results show that the excavation has little effect on the stress and strain of pile body when the distance between piles and foundation pits is more than the excavation depth of foundation pit.Moreover,when the distance between piles and foundation pits is the excavation depth,the inclination angle of pile cap is the largest.