新建隧道近接上穿对既有盾构隧道纵向变形的影响  

Influences of above-crossing tunnelling on the longitudinal deformation of existing shield tunnel

作　　者：高坤[1,2] 张志伟 梁荣柱 李忠超 田洪峰[3] GAO Kun;ZHANG Zhiwei;LIANG Rongzhu;LI Zhongchao;TIAN Hongfeng(Anhui Province Institute of Building Research&Design,Hefei 230031,China;Anhui Key Laboratory of Green Building and Assembly Construction,Hefei 230031,China;Faculty of Engineering,China University of Geosciences(Wuhan),Wuhan 430074,China;Wuhan Municipal Construction Group Co.,Ltd.,Wuhan 430023,China)

机构地区：[1]安徽省建筑科学研究设计院,安徽合肥230031 [2]绿色建筑与装配式建造安徽省重点实验室,安徽合肥230031 [3]中国地质大学(武汉)工程学院,湖北武汉430074 [4]武汉市市政建设集团有限公司,湖北武汉430023

出　　处：《安全与环境工程》2024年第2期110-119,136,共11页Safety and Environmental Engineering

基　　金：国家自然科学基金项目(41807262);住房和城乡建设部科学技术计划项目(2021-K-074);安徽省住房城乡建设科技计划项目(2020-YF44);绿色建筑与装配式建造安徽省重点实验室开放课题(2021-JKYL-004);安徽建工集团2021年度科研立项项目(2021-52ZC);武汉市市政建设集团科研项目(wszky202013);湖北省建设科技计划项目(2020-22)。

摘　　要：新建隧道近接上穿将诱发下卧盾构隧道隆起变形,预测既有盾构隧道位移发展对近接上穿施工控制和既有盾构隧道保护具有重要意义。基于两阶段法,提出新建隧道近接上穿引发既有盾构隧道纵向位移解析解;通过可考虑环间接头弱化的非连续盾构隧道模型模拟既有盾构隧道,采用Riftin地基考虑盾构隧道-土层相互作用,同时通过Mindlin经典解得到新建隧道开挖卸载应力,并作用于既有盾构隧道之上,建立新建隧道上穿作用下既有盾构隧道纵向变形解答;通过将杭州圆形顶管隧道上穿既有地铁1号线、上海地铁8号线隧道上穿既有地铁2号线两个工程案例实测值与本文方法和常用Euler-Bernoulli(EB)等效连续梁模型计算结果进行对比,验证本文方法的合理性。研究结果表明:本文方法和EB连续梁模型预测的隧道纵向位移均接近实测值;本文方法预测的隧道弯矩和接头张开量均大于EB连续梁模型;但EB等效连续梁模型预测的纵向位移曲线整体呈现为光滑连续,而本文方法预测的位移曲线是由一系列短直线连接而成,在接头处存在“尖点”。A new tunnelling crossing above with a small clearance will induce uplift of the underlying shield tunnel.Thus,predicting the existing shield tunnel displacement is very significant to above-crossing tunnelling construction control and the protection of the existing tunnel.The analytical solution for the displacement of the existing shield tunnel due to above-crossing tunnelling is proposed based on the two-stage analysis method.The existing shield tunnel was simulated by the non-continuous shield tunnel model which can weaken circumferential joint.The Riftin foundation model was adopted to consider the shield tunnel-ground interaction,The unloading stressing induced by new tunnel excavation was obtained by Mindlin classic solution,which was then imposed on the shield tunnel to establish analytical solution of the longitudinal deformation of the existing shield tunnel subjected to the construction of new tunnel above.The predictions by the proposed method were compared with field measurements and the calculation results by Euler-Bernoulli(EB)equivalent continuous beam model from Hangzhou jacking tunnel above-crossing Metro Line 1 and Shanghai Metro Line 8 crossing over Metro Line 1 to verify the feasibility of the proposed method.It shows that the tunnel displacements predicted by the proposed method and the EB continuous beam model are both close to the measured results.The bending moments and joint openings of the existing shield tunnel predicted from the proposed method are larger than those from the EB continuous beam model.However,the displacement curves predicted by the EB continuous beam model are smooth and continuous,while the displacement curves predicted by the proposed method are composed of a series of short straight lines,and significant sharp points appear in the joints.

关 键 词：隧道上穿 既有盾构隧道 环间接头弱化 纵向变形 非连续盾构隧道模型 Riftin地基模型 

分 类 号：X93[环境科学与工程—安全科学] U455[建筑科学—桥梁与隧道工程]