深基坑施工失稳破坏研究

Study on the Instability of Deep Foundation Pit Construction

城市深基坑变形过大易引起土层的失稳破坏,若不及时采取补救措施,不仅能导致基坑滑坡、上层建筑倾覆等工程事故,还对周围环境造成恶劣影响。分析深基坑施工的破坏机理和破坏形式,利用Flac3D数值分析方法对基坑的失稳破坏进行模拟,总结造成深基坑稳定性变化的各种原因,得出如下研究结论:深基坑失稳范围会随着土体黏聚力的减小而随之增大;深基坑的整体稳定性会随着内摩擦角增加而上升;抗拉强度的大小对深基坑稳定性影响极小;外荷载的增加会使稳定性系数降低,影响基坑的安全。

Cities deep pit large deformation can lead to excessive destruction of soil instability, if not timely remedial measures, not only can lead to pit landslide, superstructure overturning accident and other projects, but also have adverse effects on the surrounding environment. Analysis of the mechanism of damage and destruction in the form of deep foundation construction, the use of Flac3 D numerical analysis method to simulate excavation damage instability summarizes the factors that affect the stability of deep foundation,get the following conclusions： With decreases cohesion of soil, pit loss stable range increases; With the internal friction angle increases, the overall stability of the pit rises;The size of the tensile strength have little impact on the stability of the pit; With external loads increase,the stability coefficient is reduced, so the external loads have impacts on the security of pit. deformation.