理論研究 2024年 第53卷 第21期

DOI: 10. 7672 / sgjs2024210103

富水地層地鐵車站基坑降水開挖變形與控制措施研究

劉帥

作者簡介：

劉帥，工程師，E?mail:411187657@ qq. com

作者單位：

中鐵十八局集團(tuán)市政工程有限公司，天津 300350

摘要：

依托某地鐵車站基坑開挖工程，通過數(shù)值模擬方法，對富水地層地鐵車站基坑降水開挖變形及影響因素進(jìn)行研究，分析基坑豎向位移變化及地層滲透系數(shù)和圍護(hù)結(jié)構(gòu)厚度對基坑變形的影響，并給出基坑變形控制措施。研究結(jié)果表明，地表豎向和水平位移及圍護(hù)結(jié)構(gòu)水平位移均隨著砂卵石土層滲透系數(shù)的增大而增大，而基坑底部隆起逐漸減小；地表豎向和水平位移、圍護(hù)結(jié)構(gòu)水平位移及基坑底部隆起均隨著圍護(hù)結(jié)構(gòu)厚度的增大而減小。對于滲透系數(shù)大的地層，須采取措施減小基坑變形，可適當(dāng)增大圍護(hù)結(jié)構(gòu)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.