二次衬砌施作时机对盾构隧道纵向力学性能的影响分析  

The influence of secondary lining construction time on longitudinal mechanical properties of shield tunnel

作　　者：王宏超 胡军 周永强[2,3] 付晓东 WANG Hongchao;HU Jun;ZHOU Yongqiang;FU Xiaodong(China Railway Eryuan Engineering Group Co.,Ltd.,Chengdu 610031,Sichuan,China;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Wuhan 430071,Hubei,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中铁二院工程集团有限公司,四川成都610031 [2]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 [3]中国科学院大学,北京100049

出　　处：《隧道与地下工程灾害防治》2024年第2期99-112,共14页Hazard Control in Tunnelling and Underground Engineering

基　　金：国家自然科学基金面上资助项目(52079135)

摘　　要：为解决盾构隧道因纵向不均匀变形引起的结构局部破坏和渗漏水等病害,对盾构隧道二次衬砌施作时机的影响规律及合理施作时机进行研究,建立双层衬砌盾构隧道三维纵向精细化数值模型,模拟管片螺栓力学特性和双层衬砌层间接触面交互特性,以施作二衬时管片衬砌变形程度作为二衬施作时机,通过隧道纵向等效抗弯刚度、纵向变形及结构受力情况分析二衬施作时机对双层衬砌盾构隧道纵向力学性能的影响。研究结果表明:二衬的施作能够有效提高结构抵抗纵向变形能力,减小管片衬砌纵向内力,且施作越早效果越明显。然而,过早施作二衬会导致二次衬砌承载较大,且不能充分发挥管片的承载能力,造成结构性能的浪费。结合双层衬砌结构纵向受力情况,引入合理程度作为判断标准,确定二衬合理施作时机为管片变形达到最终变形的37.5%~62.5%。在此施作时机下,管片衬砌变形处于容许范围内,隧道结构可以同时满足工程经济性和结构可靠性的要求。To solve the problem of local damage and water seepage and leakage of lining structure caused by the longitudinal uneven deformation in shield tunnel,the influence law of construction time of the secondary lining and the reasonable construction time were researched in this paper.A three-dimension longitudinal refined numerical model of shield tunnel with double-layered lining was established,and the mechanical properties of the bolts and the interface between segment and secondary lining were realistically simulated.The deformation degree of segment lining when the secondary lining was constructed was used as the construction time of secondary lining,and the influence of the construction time of secondary lining on the longitudinal mechanical properties of double-layered lining shield tunnel was analyzed through the longitudinal equivalent flexural stiffness,longitudinal deformations and longitudinal internal forces of shield tunnel.The researches shown that the ability of shield tunnel structure to resist longitudinal deformation was improved and the longitudinal internal force of segment lining was reduced owing to the construction of secondary lining.The earlier the construction time,the better the effect.However,the secondary lining load-bearing became prominent and the loadbearing capacity of segment lining could not be utilized sufficiently when the secondary lining was constructed early,resulting in a waste of structural capacity.Considering the longitudinal internal force situation of the double-layered lining structure,the reasonable degree was introduced as the judgment criterion,and the reasonable construction time of secondary lining was determined to be 37.5%-62.5%.In this condition,the segment lining deformation was within the tolerance range,and the requirements of engineering economy and structural reliability of tunnel structure could be satisfied at the same time.

关 键 词：盾构隧道 双层衬砌 精细化模型 二衬施作时机 纵向力学性能 

分 类 号：U451[建筑科学—桥梁与隧道工程]