临近既有地铁车站的基坑变形性状研究

通过36组二维有限元数值模拟，研究了不同参数（基坑与地铁车站距离D，基坑开挖深度 ）组合下临近既有地铁车站的基坑变形性状，并与邻近无车站时的基坑变形性状进行对比分析。研究结果表明：（1）当邻近存在地铁车站时，靠近车站一侧的地下连续墙最大侧移量减小，另一侧的地下连续墙最大侧移量增加；（2）当基坑开挖深度接近或超过地铁车站底板埋深时，车站对远离车站侧的基坑墙后地表沉降的影响显著，但不明显改变地表沉降影响范围和最大沉降值位置；（3）D较小时，随着 的增大，地铁车站的“遮拦效应”越来越显著。而当D逐渐增大时， 对地铁车站“遮拦效应”的影响逐渐减弱。（4）地铁车站的存在与否对基坑远离车站侧最大地表沉降和最大地下连续墙侧移的比值（δevm / δehm）几乎没有影响，并且，该值受D与 的影响较小。

Investigation on deformation behaviors of foundation pit adjacent to existing metro stations

Deformation behaviors of foundation pits adjacent to metro stations in different parameter groups (the distance, D, between the existing metro stations and foundation pits, the depth of the excavations, ) were examined via 36 comprehensive two-dimensional finite element parametric studies, which were compared with those without metro stations nearby. On the basis of the numerical analysis results, some major findings were obtained: (1) Maximum deflections of diaphragm walls closer to the metro stations became smaller and those of another side became greater; (2) The existing of metro stations had a remarkable influence on the ground settlements behind the walls far away from the metro stations when was closer to or greater than the depth of base slabs of metro stations. However, the settlement influence zone and the location of maximum ground settlement were not changed obviously; (3) As the increasing of , the shielding effect of metro stations became significant gradually when D was small. Nevertheless, the effect of on the shielding effect weakened by degrees as D became larger; (4) The ratios of maximum ground settlements behind the walls of excavations far away from the metro stations over the corresponding maximum diaphragm wall lateral deflections, δevm / δehm, were almost not effected by the existing metro stations. Moreover, δevm / δehm were effected by D and slightly.