地铁盾构隧道近接下穿既有铁路隧道加固范围优化设计——以南宁地铁4号线下穿既有槎路隧道为例  

Optimization Design of Reinforcement Range When a Metro Shield Tunnel Crossing underneath an Existing Railway Tunnel:a Case Study on Nanning Metro Line 4 Crossing underneath Existing Chalu Tunnel

作　　者：唐志辉 TANG Zhihui(China Railway Liuyuan Group Co.,Ltd.,Tianjin 300308,China)

机构地区：[1]中铁第六勘察设计院集团有限公司,天津300308

出　　处：《隧道建设（中英文）》2020年第8期1185-1191,共7页Tunnel Construction

基　　金：中铁第六勘察设计院集团有限公司重点科研课题(KY-2015-08)。

摘　　要：为解决城市地铁盾构隧道近接下穿既有铁路隧道时难以合理经济地估算交叉段加固范围的问题,依托南宁地铁4号线那历村站—那洪立交站区间隧道下穿既有槎路隧道工程,提出基于强度折减系数法的地铁盾构隧道近接下穿既有铁路隧道加固范围优化设计方法,并通过监测数据验证该方法的有效性。研究结果表明:1)以特征点突变作为实际隧道施工安全性的判据存在一定的局限性,可采用满足变形控制标准下的最大折减系数作为综合安全系数;2)加固圈厚度系数和长度系数与铁路隧道系统综合安全系数呈幂函数关系;3)所拟定的加固方案能有效控制既有上伏铁路隧道的沉降变形。It is difficult to rationally and economically estimate the reinforcement range of the intersection between the urban metro shield tunnel and existing railway tunnel.As a result,an optimization design method based on the strength reduction coefficient method for Nalicun Station-Nahong Interchange Station tunnel on the Nanning Metro Line 4 crossing underneath existing Chalu Tunnel is proposed,and the effectiveness of the method is verified by monitoring data.The research results show that:(1)There are certain limitations in using the characteristic point mutation as the criterion for the actual tunnel construction safety,and the maximum reduction coefficient under the deformation control standard can be adopted as the comprehensive safety coefficient.(2)The reinforcement thickness coefficient and length coefficient have a power function relationship with the comprehensive safety coefficient of the railway tunnel system.(3)And the monitoring feedbacks show that the proposed reinforcement scheme can effectively control the settlement and deformation of existing railway tunnel.

关 键 词：盾构隧道 下穿施工 既有铁路隧道 加固范围 强度折减法 

分 类 号：U459[建筑科学—桥梁与隧道工程]