地铁交叠车站超深基坑施工对既有线的影响OA

Excavation of deep foundation pits at the overlapping metro station leads to changes in the stress state and mechanical properties of the soil within a certain range of the surrounding area,which adversely affects the existing metro lines.Therefore,it is important to study the influence of excava-tion disturbance on the overall pit deformation,and then clarify the impact of ultra-deep foundation pit construction on existing metro lines.Taking the ultra-deep foundation pit project of the Minggugong overlapping station of Nanjing Metro Line 6 as the background,the deformation characteristics of the overall pit structure after excavation of the south and north foundation pits of Minggugong station were analyzed using the Plaxis3D numerical simulation method,and the influence of ultra-deep foundation pit excavation on the existing lines under complex environmental conditions was investigated.The re-sults showed that after the pit excavation was completed,in terms of vertical displacement,the settle-ments of the existing up-line track,down-line track,and existing line station were-1.48 mm,-1.22 mm,and-8.19 mm,respectively.The settlement of the existing line caused by the south pit,which was excavated using a combination of inverse and sequential construction methods,ac-counted for 69.84% of the total settlement,and the inverse method had a better control effect on the deformation of the pit and the existing line track.In terms of horizontal displacement,the displace-ments of existing up-line track,down-line track,and existing line station were 2.61 mm,2.37 mm,and 11.83 mm,respectively,and the direction was towards the south pit.Excavation caused the track bed to shift towards the excavation side of the pit,and the closer the distance to the pit,the larger the track displacement response.