悬臂桩桩径变化对基坑抗冻胀性能分析

Analysis of anti-frost heave performance of foundation pit with changes of cantilever pile diameter

我国疆域辽阔,冬季处于季冻区的省份面积约占一半,冬季基坑开挖的土体冻胀问题难以避免。本文就基坑抗冻胀性能进行研究,采用悬臂桩作为基坑支护方式,通过有限元数值模拟软件具体分析悬臂桩桩径变化对季冻区已冻结基坑的影响效果。得到结论如下:已冻结土体中基坑在受到冻胀力的作用下其桩侧水平位移能够达到未冻结土体的四倍。随着悬臂桩桩径增加,桩侧水平位移减小,峰值减少36.2%;随着悬臂桩桩径增加,桩侧冻胀力增大,峰值增大78.4%。

Our country has a vast territory,and about half of the provinces are in the seasonal freezing zone in winter.The problem of soil frost heave in excavation of foundation pits in winter is unavoidable.In this paper,the anti-frost heave performance of the foundation pit is studied,the cantilever pile is used as the foundation pit support method,and the effect of the change of the cantilever pile diameter on the frozen foundation pit in the seasonal frozen area is analyzed by the FLAC3D finite element numerical simulation software.The conclusions are as follows.The horizontal displacement of the pile side of the foundation pit in the frozen soil can reach four times that of the unfrozen soil under the action of the frost heave force.As the diameter of the cantilever pile increases,the horizontal displacement of the pile side decreases,and the peak value decreases by 36.2%.With the increase of the cantilever pile diameter,the frost heave force on the pile side increases,and the peak value increases by 78.4%.