蠕滑错断-强震时序作用下跨活断裂 隧道变形破坏机制初步研究  

Deformation and failure of a tunnel subjected to the coupling effect of a quasi-static faulting and seismic impact

作　　者：崔臻[1,2] 盛谦 李建贺[3] 付兴伟 CUI Zhen;SHENG Qian;LI Jian-he;FU Xing-wei(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;Changjiang Institute of Survey,Planning,Design and Research Co.,Ltd.,Wuhan,Hubei 430010,China;China Three Gorges Corporation,Beijing 100038,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 [3]长江勘测规划设计研究有限责任公司,湖北武汉430010 [4]中国长江三峡集团有限公司,北京100038

出　　处：《岩土力学》2022年第5期1364-1373,共10页Rock and Soil Mechanics

基　　金：国家自然科学基金资助项目(No.51779253,No.52079133);深部岩土力学与地下工程国家重点实验室开放基金课题(No.SKLGDUEK1912);长江科学院开放研究基金资助项目(No.CKWV2019746/KY);暨南大学“重大工程灾害与控制”教育部重点实验室项目(No.20200904002)。

摘　　要：在以往对跨活断裂隧道变形破坏机制研究中,往往分别单独研究蠕滑错断与强震两种效应,忽略了在强震区两种效应往往同时对隧道具有威胁的可能性。基于此,讨论了蠕滑错断-强震时序作用对强震区隧道的影响。在室内试验数据的基础上,考虑相对错动条件下岩石-衬砌接触面、隧道混凝土衬砌材料的非线性弱化特征,研究隧道在先后发生活断裂错断与强震作用下的变形响应与破坏特征。引入了“柔性铰接”设计概念作为隧道的针对性工程措施,并验证了铰接设计的效果。开展了详细的参数研究,讨论了铰接设计中一些重要设计参数的影响。研究结果表明:(1)仅受到断层作用时,隧道的影响与破坏仅限于断层带部分,而隧道的其他部分基本保持相对完好;(2)隧道衬砌在蠕滑错断-强震时序作用下,隧道衬砌出现了明显的椭圆形变形和顶板沉降,导致隧道衬砌沿起拱线也出现明显的破坏现象。具有初始错断损伤的隧道在地震作用下会遭受更严重的破坏,破坏程度随初始错断距离的增加而增加;(3)铰接设计可以在时序组合作用下减少相对变形并提高隧道的安全程度,但铰接设计带来的安全程度的提高仅限于设防范围内;(4)建议设防长度的最佳范围为略大于断层宽度即可,节段长度越小,对改善隧道安全裕度越有利,而增加错断缝宽度几乎并不能提高隧道在蠕滑错断-强震时序组合下的表现。研究成果作为初步探索,可为进一步提高我国西部强震区地下工程的抗震抗错断能力提供一定的参考。In previous studies on the mechanisms of deformation and failure of tunnels across active faults,the two effects of quasi-static faulting and seismic excitation were often studied separately,ignoring the possibility that the two effects are often threatening to the tunnel at the same time in the high seismic risk zone.In this study,sophisticated numerical methods and constitutive models were used to study the effect of combined fault rupture deformation and subsequent seismic excitation upon a tunnel.The weakening of the rock-tunnel interface under relative dislocation and degradation of the concrete material in the tunnel liner were considered.The deformation response and failure mechanism of the tunnel subjected to combined fault rupture deformation and subsequent seismic excitation were investigated.Relative deformation time histories,plastic strain,tensile strain of the tunnel were studied.And the performance of“joint”design was numerically verified,followed by a detailed parameter study that aimed to provide deep insight into the design factors of the technique of“flexible jointing”.The influences of some important factors were investigated,such as the range of the joints,length of the segments,and infill material properties.The results indicated that:(1)When solely affected by the faulting,the influence and damage to the tunnel are limited within the fault zone,while the other parts of the tunnel remain relatively intact.(2)Under the combined fault rupture deformation and subsequent seismic excitation,notable ovaling deformation and roof settlement would occur in the tunnel liner,also the tunnel spring line would suffer significate damage.Tunnels with initial faulting induced damage would suffer more damage under the action of earthquakes,and the damage degree increases with the increasing initial faulting distance.(3)The flexible joint design could decrease the tunnel’s relative deformation under the combined effect and enhance the stability of the tunnel.However,it should be noted that this bene

关 键 词：隧道 断层错动 强震 岩-混凝土相互作用 柔性接头 

分 类 号：TU452[建筑科学—岩土工程]