开挖扰动诱发深基坑水平位移特性分析

ANALYSIS OF HORIZONTAL DISPLACEMENT CHARACTERISTICS OF DEEP FOUNDATION PIT INDUCED BY EXCAVATION DISTURBANCE

为研究在微型钢管桩+锚索/锚杆支护下,土岩组合地层深基坑施工过程中土体水平位移的变化规律,以青岛市鞍山路地铁车站深基坑工程为例,运用有限元模拟与现场监测数据相结合的方法进行对比分析。研究结果表明,基坑施工的过程中土体位移主要发生在上部土层以及弹性模量较低的强风化岩层;随着基坑开挖深度的不断增加,基坑侧壁同一位置的水平位移不断增加;基坑土体侧向变形趋势从总体上近似为“弓字形”分布。研究结果对类似工程具有一定的指导作用。

This paper studies the variation law of soil horizontal displacement during the construction of deep foundation pits in soil rock composite strata under the support of micro steel pipe piles and anchor cables/anchor rods.Taking a deep foundation pit project of Anshan Road subway station in Qingdao as the case,a comparative analysis is conducted using finite element simulation and on-site monitoring data.The results indicate that soil displacement mainly occurs in the upper soil layer and strongly weathered rock layers with lower elastic modulus during the construction of foundation pits.The horizontal displacement of the side wall of the foundation pit at the same position increases as the excavation depth of the foundation pit increases.The lateral deformation trend of the foundation pit soil is generally approximately a bow shaped distribution.