西安地铁穿越地裂缝段隧道扩挖施工参数优化  

Construction Parameters Optimization of Tunnel Expansion Excavation for Xi’an Subway Through Ground Fissures Section

作　　者：高强 祝朋辉 何朝君 GAO Qiang;ZHU Penghui;HE Chaojun(Guangzhou Metro Design&Research Institute Co.Ltd.,Guangzhou 510010,China;School of Highway,Chang’an University,Xi’an 710064,China)

机构地区：[1]广州地铁设计研究院股份有限公司,广州510010 [2]长安大学公路学院,西安710064

出　　处：《铁道建筑》2023年第12期1-5,共5页Railway Engineering

基　　金：西安市轨道交通集团有限公司科技项目(D15-YJ-152021006);广州地铁设计研究院股份有限公司科技项目(KY-2020-003)。

摘　　要：采用正交试验设计确定数值模拟工况,研究西安地铁15号线府君庙村站—祝村站区间隧道扩挖施工参数对拱顶、地表沉降的影响程度和最优参数组合。结果表明:扩挖施工参数的影响程度排序为施工工法>施工进尺>加固圈厚度;微台阶法和全断面法扩挖均满足地表沉降控制要求,考虑到临时横撑的受力特性和施工干扰问题,建议采用全断面法;增大加固圈厚度对地表沉降的控制效果有限,从经济性考虑建议加固圈厚度取3.0 m;确定施工进尺须考虑盾构管片环宽,环宽1.0 m时建议施工进尺取0.50 m,环宽1.5 m时建议施工进尺取0.75 m。该区间隧道设防段未改变管片环宽(1.5 m),已采用本文建议的全断面法+加固圈厚度3.0 m+施工进尺0.75 m的参数组合施工。目前左线已完成10环扩挖,地表累计沉降与模拟结果相差不大,满足规范要求。Using orthogonal experimental design to determine numerical simulation conditions,the degree of influence and optimal parameter combination of tunnel expansion excavation construction parameters on tunnel vault and surface settlement in the section between Fujunmiaocun Station-Zhucun Station on Xi’an Subway Line 15 were studied.The results indicate that the order of the degree of influence of expansion excavation construction parameters is construction method>construction footage>reinforcement ring thickness.Both the micro step method and the full section method for excavation meet the requirements of surface settlement control.Considering the stress characteristics of temporary cross braces and construction interference issues,it is recommended to use the full section method.Increasing the thickness of the reinforcement circle has limited control effect on surface subsidence.From an economic perspective,it is recommended to take a thickness of 3.0 m for the reinforcement circle.The determination of construction footage must consider the shield tunnel segment ring width.When the ring width is 1.0 m,it is recommended to take a construction footage of 0.50 m,and when the ring width is 1.5 m,it is recommended to take a construction footage of 0.75 m.The defensive section of the tunnel in this section has not changed the width of segment ring(1.5 m),and has been constructed using the parameter combination of“full section method+reinforcement ring thickness of 3.0 m+construction footage of 0.75 m”recommended in this article.At present,the left line has completed 10 ring expansion excavations,and the cumulative surface settlement is not significantly different from the simulation results,meeting the regulatory requirements.

关 键 词：地铁隧道 施工参数优化 数值模拟 正交试验 地表沉降 西安地裂缝 扩挖施工 

分 类 号：U455.4[建筑科学—桥梁与隧道工程]