盾构隧道施工期衬砌管片受力特性及其影响分析

Analysis of mechanical characteristic of shield tunnel segments lining and its influence during construction

针对施工期盾构隧道管片衬砌的受力特性及其施工荷载对管片结构造成的影响开展研究。首先,对施工期管片所受施工荷载进行系统总结,包括千斤顶推力、注浆压力、上浮力、盾壳作用力、拼装荷载及其他荷载等;进而将施工阶段管片衬砌的受力特性归纳为典型三维特性、不确定性及不可忽视性等三方面。在此基础上,对施工荷载对管片结构的影响进行了分析讨论,包括施工期的管片裂缝、局部破损、止水条损坏、管片渗漏、管片错台等。最后,从掘进千斤顶控制、注浆压力控制、螺栓二次预紧等角度对施工期盾构隧道的管片破损保护工作提出了建议。分析表明,对盾构隧道施工期管片受力特性及其影响的研究亟待深入,管片设计及相关规范亦应更加重视施工荷载的作用及其影响。

The mechanical characteristic of shield tunnel segments lining and its influence during construction are analyzed.Firstly,the construction loads are divided into jack thrust force,grouting force,buoyancy,shield shell press,installation load,and other loads,etc.Then,the mechanical characteristic of shield tunnel segments lining is summarized as the typical three-dimensional character,indetermination,and the innegligible character.Afterwards,the influence of the construction loads on segments lining is discussed,including the cracks,partial breakage,sealing strip falling,segments leakage,and segments dislocation.Finally,some advices to protect the shield segments during construction are presented,such as jack controlling,grouting pressure controlling,and the repeated tightening the bolts.The result shows that the analysis of the mechanical characteristic of shield tunnel segments lining and Its influence during construction is imperative,and the construction loads should be emphasized in segments designing and the correlative criferia.