地铁隧道变形分析及治理加固技术研究

Study on the Deformation Analysis and Reinforcement Technology of Subway Tunnel

软土地层地铁隧道由于相邻深大基坑开挖卸荷、地下水抽降、地铁隧道上方加卸载、新建高层建筑沉降等因素,会对既有隧道结构造成扰动导致严重病害。目前对既有地铁隧道变形治理加固的各项措施在工程实践中得到一定应用,但对其作用机理仍缺乏系统性理论研究和规律性认识。本文以南京地铁2号线西延天保街站-青莲街站区间隧道沉降及收敛变形异常区段治理加固施工为例,结合理论分析、有限元数值模拟及现场监测数据分析等手段,验证MJS工法桩隧底加固、管片深孔注浆、隔离桩、钢环加固等综合措施在控制隧道结构变形和加固效果,对类似隧道变形治理具有一定借鉴意义。

Owing to the excavation and unloading of the adjacent deep and large foundation pit,the pumping of groundwater,the unloading and ballasting of the subway tunnel,the settlement of the new high-rise building and other factors,the existing tunnel structure will be disturbed and some serious diseases will be caused in the soft soil layer.At present,various measures for the deformation treatment and reinforcement of existing subway tunnels have been somewhat applied in engineering practice.However,the principle of action still lacks systematic theoretical research and understanding of regularity.This paper takes the reinforcement of the abnormal section of tunnel settlement and convergent deformation between Tianbaojie Station and Qinglianjie Station on the west extension section of Nanjing Metro Line 2 as an example,and verifies the effects of some comprehensive measures such as tunnel bottom reinforcement by MJS,deep hole grouting of segment,isolation piles,and steel ring reinforcement in controlling the deformation of the tunnel structure and strengthening treatment through theoretical analysis,finite element numerical simulation and field monitoring data analysis,etc.The research results will have certain reference significance for the deformation treatment of similar tunnels.