新建地铁车站施工对既有地铁车站的影响研究

Study on the impact of new metro station construction on existing metro stations

文章基于苏州地铁某车站,采用现场实测与数值模拟相结合的方法,研究深基坑开挖对周围土体影响规律,分析新建车站施工对临近既有车站受力变形影响。经研究,基坑开挖前2/3深度时,对周围土体扰动主要表现为沉降范围扩大,继续开挖及随后的回筑阶段对周围土体的扰动以沉降量增加为主;新建车站施工,既有车站地下一层侧墙受压,最大压应力出现在顶板高度处,地下二层侧墙以受拉为主,且拉应力处于较高水平,最大拉应力出现在该层中部;新建车站施工时,既有车站靠向基坑方向倾斜;既有车站顶板靠近基坑一端出现沉降,随开挖深度增加顶板逐渐抬升,开挖过程中沉降值减小45.8%。

Based on a station of Suzhou metro,this article adopts a method that combines on-site measurements and numerical simulations to study the influence of deep foundation pit excavation on the surrounding soil,and analyze the influence of the construction of new station on the stress and deformation influence against the adjacent existing station.Upon research,during the excavation of the first 2/3 depth of foundation pit,the perturbation of the surrounding soil is mainly represented by the expansion of the settlement range,and for the continuing excavation and the subsequent reverse construction stage,the perturbation of the surrounding soil is mainly represented by the increase of the amount of settlement;in the construction of new stations,the side walls of the first underground layer of the existing station are subjected to compression,with the maximum compressive stress appearing in the height of the top plate,and the side walls of the second underground layer are mainly subjected to tension,and the tensile stress is at a higher level,with the maximum tensile stress appearing in the middle of the layer;when the new station is under construction,the existing station is tilted in the direction of the foundation pit;settlement occurs at one end of the top plate of the existing station near the foundation pit,and the top plate is gradually lifted with the increase of the excavation depth,and the settlement value reduced by 45.8%in the process of excavation.