地铁车站基坑围护结构内力与变形规律分析

给出了森公地铁车站深基坑围护和变形监测方案,对基坑变形规律进行了现场监测研究,重点对基坑围护桩的水平位移和钢支撑的轴力变化进行了现场监测。结果表明:桩顶水平位移反映围护结构的顶部变形情况,能直接反映围护结构的变形特性,是评价围护结构安全状况的重要指标;在有钢支撑作用的情况下,围护桩变形最大的部位位于距桩顶2/3基坑开挖深度处;钢支撑轴力随开挖深度增加而增加,其大小变化与开挖方式、开挖速度以及天气等因素有关。

Inner force of bracing structure and deformation laws of foundation pit for subway station

The retaining plan and deformation monitoring plan are given and the field monitoring study is completed on the foundation pit deformation,especially on the horizontal displacement of the retaining pile body and the inner axial force of steel props.The study shows the deformation characteristics of bracing structure is related to the horizontal displacement of the retaining pile top,which is a important criterion of the safety of condition of bracing structure.With the effect of bracing structure,the largest deformation appears at the depth of 2/3 of the pile length rather than on the pile top.The inner force of steel props increases with the increment of the excavation depth,and its value changes with the varieties of construction case,excavation mode,velocity and temperature.