富水地层地铁车站结构抗浮措施性能分析

Performance analysis of anti-floating measures for metro station structure in water-rich strata

以某沿海城市地铁车站结构为例,通过室内单桩竖向抗压静载试验,计算单桩极限侧阻力,理论验算和MIDAS有限元软件数值模拟相结合,对比分析不同抗浮措施下车站结构底板位移、变形大小。结果表明:围护结构法抗浮,车站底板竖向位移得到控制,但结构底板变形较大,底板水头高度为17.4 m时,底板最大变形5.75 mm;抗浮锚杆和抗浮桩可有效减小结构底板变形,底板水头高度为17.4 m时,两种抗浮措施下底板最大变形分别为2.37和2.04 mm;抗浮组合措施能够发挥各自优势,抗浮效果明显,对结构变形控制较好;排水减压法基于减小结构水浮力原理抗浮,抗浮效果显著。

In order to compare and analyze the displacement and deformation of the station floor,a metro station in a coastal city was taken as an example for analysis,while the ultimate lateral resistance of single pile was calculated by indoor single-pile vertical compression static load test,and the method of combining theoretical calculation with MIDAS finite element software numerical simulation was adopted.Results demonstrate that when the retaining structure method is used to resist floating,the vertical displacement of the station floor is effectively controlled,but the structural floor is greatly deformed,and the maximum deformation of the floor is 5.75 mm when the hydraulic head of the floor is 17.4 m;the anti-floating anchor rod and the anti-floating pile can effectively reduce the deformation of structural floor,and when the hydraulic head of the floor is 17.4 m,the maximum deformation of the floor under the two anti-floating measures is 2.37 and 2.04 mm;the anti-floating combination can give full play to their respective advantages,producing the most obvious anti-floating effect and a better control of the structural deformation;the method of drainage and decompression is based on the principle of reducing the buoyancy of the structure,and the anti-floating effect is significant.