厚冲积黏性土层基坑支护结构力学行为研究

Mechanical Behavior of Deep Foundation Pit Support Structure in Alluvial Stratum

为研究厚冲积黏性土层基坑桩锚支护结构在基坑开挖支护过程中的力学行为,以济南市某大型深基坑为工程背景,通过理正深基坑、FLAC3D软件对不同工况下桩锚支护结构体系进行了工程试算与数值模拟。结果表明:理正深基坑软件推知围护桩水平位移、弯矩和剪力最大值分别为-42.44mm、684.53kN·m和183.56kN,3道锚索轴力分别为125.3kN、185.3kN和155.3kN;采用FLAC3D软件模拟求得基坑开挖时地表沉降、围护桩水平位移最大值分别为35.4mm和37.6mm,3道锚索轴力分别为148kN、202kN和186kN。经对比分析可知,数值模拟误差可控制在20%之内。

To study the mechanical behavior of pile anchor retaining structure during the foundation excavation and support process in alluvial stratum, taking a large deep foundation pit in Jinan City as the engineering background, Rational software for deep foundation pit and FLAC3D are used to carry out engineering trial calculation and numerical simulation for the structure of piles and cables in different conditions. The result shows that the maximum amount of pile displacement, moment and shear force derived by Rational excavation software, are -42.44 mm, 684.53 kN·m, 183.56 kN respectively, the maximum values of three anchors′ axial forces are 125.3 kN, 185.3 kN, 155.3 kN respectively. By using FLAC3D, the maximum values of surface subsidence, horizontal displacement of retaining pile are 35.4 mm, 37.6 mm respectively and the maximum values of three anchors′axial forces are 148 kN, 202 kN, 186 kN respectively. The numerical simulation error could be controlled within 20% according to a comparative analysis.