理论研究 2024年 第53卷 第21期

DOI: 10. 7672 / sgjs2024210103

富水地层地铁车站基坑降水开挖变形与控制措施研究

刘帅

作者简介:

刘帅,工程师,E⁃mail:411187657@ qq. com

作者单位:

中铁十八局集团市政工程有限公司,天津 300350

摘要:

依托某地铁车站基坑开挖工程,通过数值模拟方法,对富水地层地铁车站基坑降水开挖变形及影响因素进行研究,分析基坑竖向位移变化及地层渗透系数和围护结构厚度对基坑变形的影响,并给出基坑变形控制措施。研究结果表明,地表竖向和水平位移及围护结构水平位移均随着砂卵石土层渗透系数的增大而增大,而基坑底部隆起逐渐减小;地表竖向和水平位移、围护结构水平位移及基坑底部隆起均随着围护结构厚度的增大而减小。对于渗透系数大的地层,须采取措施减小基坑变形,可适当增大围护结构厚度以控制基坑底部隆起。

English:

Based on the excavation project of a subway station foundation excavation numerical simulationmethods were used to study the deformation and influencing factors of dewatering excavation of a subwaystation foundation excavation in water⁃rich stratum. The vertical displacement changes of the foundationexcavation, the permeability coefficients, and the thickness of enclosure structures were analyzed, andcontrol measures for foundation excavation deformation were proposed. The research results show that thevertical and horizontal displacement of the ground surface and the horizontal displacement of the enclosurestructure both increase with the increase of the permeability coefficient of the sand and gravel soil layer,while the uplift at the bottom of the foundation excavation gradually decreases. The vertical and horizontaldisplacement of the ground surface, the horizontal displacement of the enclosure structure, and the upliftat the bottom of the foundation excavation all decrease with the increase of the thickness of enclosurestructures. For strata with high permeability coefficient, measures should be taken to reduce thedeformation of the foundation excavation, and the thickness of the enclosure structure can beappropriately increased to control the uplift at the bottom of the foundation excavation.