钢支撑支锚刚度对基坑围护结构的影响研究

Influence Study on Steel Support Anchor Stiffness on Foundation Pit Enclosure Structure

为研究钢支撑支锚刚度对基坑围护结构的影响,文章以福州地铁潘墩站深基坑工程为背景,运用控制变量法,通过理正深基坑计算软件对不同钢支撑支锚刚度工况下深基坑进行计算分析,得出不同钢支撑支锚刚度下支护结构最大侧向位移、内力、基坑周边地表沉降及支撑轴力变化规律。研究结果表明:钢管内支撑刚度从200MN/m 2增加到600MN/m 2,钻孔灌注桩侧移量减小,地表沉降量降低,钻孔灌注桩迎土侧弯矩、背土侧弯矩呈减小趋势,钢支撑轴力增大,钢支撑对背土侧地下钻孔灌注桩的约束大于迎土侧。适当增加内支撑刚度可控制周边土体变形。

Pandun Road Station deep foundation pit project of Fuzhou Subway is adopted as the background in the paper in order to study the influence of the steel support anchor stiffness on the enclosure structure of the foundation pit.The method of control variables is applied to calculate and analyze the deep foundation pit under different steel support anchor stiffness conditions through Lizheng Deep Foundation Pit Calculation Software.The change laws of enclosure structure maximum lateral displacement,internal force,foundation pit surrounding ground settlement and bracing axial force under different steel support anchor stiffness conditions are obtained.The research results show that:the stiffness of the steel pipe internal support increases from 200MN/m 2 to 600MN/m 2.The lateral displacement of the bored piles is decreased.The surface settlement is decreased.The bending moment of the bored pile towards the soil side and the bending moment of the soil side of the bored pile are decreased.The axial force of the steel support is increased.The constraint of the steel support on the bored pile on the soil side is greater than that on the soil side.The deformation of surrounding soil can be controlled by appropriately increasing the stiffness of internal support.