“门式结构”加固对近填海区域开挖基坑下方地铁隧道的影响分析

Analysis of the Impact of“Gate Structure”Reinforcement on Subway Tunnels Underneath Excavated Foundation Pits in Near Reclamation Areas

近填海区域由于深厚填土的流变流塑特性,极易被基坑开挖所扰动导致对周边重要建构筑物产生影响。地铁隧道作为现代城市的交通命脉,不可避免地在已建地铁隧道附近出现各种各样的基坑工程。当基坑工程位于地铁盾构区间上方时,由于土方开挖卸荷导致坑底隆起,盾构隧道受其影响导致上浮,当隧道结构变形超过设计承受极限而产生破坏时,会直接导致结构损坏,影响轨交安全。论文通过对某近填海区域开挖基坑下方地铁隧道进行有限元模拟“门式结构”加固效果,期望对类似项目的地铁隧道保护提供针对性的措施。

Due to the rheological and flow-plastic properties of deep fills in areas near reclamation,they are easily disturbed by excavation of foundation pits,which may have an impact on surrounding important buildings.As the subway tunnel is the lifeblood of modern city transportation,various foundation pit projects inevitably occur near existing subway tunnels.When the foundation pit project is located above the subway shield section,the bottom of the pit will bulge due to the unloading of earthwork excavation,and the shield tunnel will be affected by this and cause it to float.When the tunnel structure deforms beyond the design endurance limit and is damaged,it will directly lead to structural damage and affect rail transit safety.This article conducts finite element simulation of a subway tunnel under an excavation foundation pit in a near-reclamation area of the reinforcement effect of“Gate structure”,hoping to provide targeted measures for the protection of subway tunnels in similar projects.