浅埋无中导洞连拱隧道先行洞衬砌承担围岩荷载确定方法  

A method for determining surrounding rock load borne by antecedence tunnel lining of shallowly buried double-arch tunnel without middle drift

作　　者：汤华[1] 姜成业 邓琴[1] 毕钛俊 秦雨樵 TANG Hua;JIANG Cheng-ye;DENG Qin;BI Tai-jun;QIN Yu-qiao(State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,Hubei 430071,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071 [2]中国科学院大学,北京100049

出　　处：《岩土力学》2024年第4期1170-1180,共11页Rock and Soil Mechanics

基　　金：云南省交通运输厅科技创新及示范项目(云交科教[2019]79号)。

摘　　要：不同于常规隧道衬砌结构,无中导洞连拱隧道先行洞衬砌施作稳定后还要受到邻近后行洞开挖的二次扰动,后行洞开挖对先行洞衬砌受力的影响不可忽视。依托杨家寨公路隧道工程,基于考虑了后行洞开挖影响的隧道围岩压力计算方法,结合现场监测位移数据采用荷载-结构法进行位移反分析,提出了一种确定浅埋无中导洞连拱隧道先行洞衬砌承担围岩荷载的方法,最后和衬砌背后围岩荷载现场监测值进行对比验证。研究结果表明:后行洞开挖对先行洞衬砌承担围岩荷载的影响较为显著,监测点增长幅度均值高达142%;先行洞衬砌受力呈现“拱腰较小,拱顶及拱肩较大”的分布规律,且靠近后行洞一侧拱肩位置受力最大;通过现场监测位移反分析得到的先行洞衬砌受力结果和现场监测结果较为一致,论证了该方法的合理性和实用性,研究成果可为无中导洞连拱隧道结构设计提供参考。Unlike conventional tunnel lining structures,the antecedence tunnel lining is subject to secondary disturbances from the later excavated tunnel excavation after the lining has been stabilized.The excavation impact of the later excavated tunnel on the surrounding rock pressure acting on the antecedence tunnel lining cannot be ignored.Relying on Yangjiazhai tunnel project,a calculation method for surrounding rock pressure that accounts for the influence of the second tunnel excavation has been developed.This method,in combination with on-site monitoring displacement data and utilizing the load-structure method for inverse analysis,proposes a means of determining the load acting on the antecedence tunnel lining.The field-measured values of the surrounding rock pressure behind the lining were used for comparison and verification.The study results have yielded important insights:1)The impact of the second tunnel excavation on the first tunnel lining’s ability to withstand surrounding rock pressure is substantial,with the average increase in monitoring points reaching as high as 142%.2)The pressure acting on the antecedence tunnel lining follows a distribution pattern of being lower at the waist of the arch and higher at the top and the shoulder,with the shoulder of the arch near the later excavated tunnel experiencing the greatest pressure.3)The results of the surrounding rock loading obtained from the inverse analysis are more consistent with the field monitoring results,which argues for the soundness and practicality of the approach,and providing a reference basis for the structural design for the double-arch tunnel without middle drift.

关 键 词：荷载结构法 无中导洞连拱隧道 位移反分析 衬砌受力 

分 类 号：TU452[建筑科学—岩土工程]