川藏铁路昌都—然乌段班公湖—怒江结合带的工程效应研究  

Engineering Effects of Bangong Lake-Nujiang Junction Zone in Sichuan-Tibet Railway of Changdu-Ranwu

作　　者：刘凯[1] 李渝生[1] 蒋良文[2] 毛邦燕[2] 黄超[1] 易树健 

机构地区：[1]成都理工大学地质灾害防治与地质环境保护国家重点实验室,成都610059 [2]中铁二院工程集团有限责任公司,成都610031

出　　处：《科学技术与工程》2018年第2期42-48,共7页Science Technology and Engineering

基　　金：中国铁路总公司科技研究开发计划重大课题-川藏铁路修建关键技术研究(2014G004)资助

摘　　要：班公湖—怒江结合带复杂的地质建造-构造、断层活动性以及地壳岩体应力-形变状态等问题,对川藏铁路"昌都—然乌"段铁道工程建设有着极大的影响和制约。为探究其工程效应,在现场地质研究基础上结合数值计算,对其构造动力学特征及地壳岩体应力-形变作用进行深入分析。班公湖—怒江结合带总体处于相对稳定状态,北东边界断裂活动性较强;结合带地应力水平较高,地壳岩体的应力形变作用表现为压缩变形;上地壳岩体沿壳内低速层做近水平运移,驱动结合带及南西侧地块向NE推移俯冲;结合带岩体对构造应力消减作用不明显,两侧应力水平差异较小。结合带的关键工程地质问题是兼有右旋剪切作用的强压缩变形,其南西侧冈底斯-念青唐古拉陆块主要是高地应力岩体力学效应问题,北东侧南羌塘—左贡陆块主要是软岩隧道大变形问题。Changdu-Ranwu railway project is located in Bangong Lake-Nujiang junction zone.The geology characteristic,fault activity and stress-strain appearance have significant influences and restrictions on the project.Based on field investigation of geological formation and structure,Conbining with numerical calculation,the structural dynamic characteristics and the crust stress-strain action are analyzed,and the engineering effects are explored.The results are as follows：Bangong Lake-Nujiang junction zone is at steady state overall but the eastern fault has shown high activity.The whole stress level in junction zone is quite high and causes NW-NWW compression deformation.The cover sediments and crystalline basement flow upon the low-velocity zone and the soft lower crust,the junction zone and Gangdese Nyainqentanglha block dive toward northeast.The stress between the eastern and western block is barely equal as the junction zone is compressed tightly and can only dissipate few energy from west.The key engineering geological problems are different in separate regions.Junction zone has shown high compression with dextral shearing,the western block Gangdese-Nyainqentanglha reflects high ground pressure and rockmass effects,the eastern block South Qiangtang-Zuogong will encounter high deformation problems in soft rock tunnels.

关 键 词：川藏铁路 班公湖—怒江结合带 地质建造-构造 断层活动性 工程效应 

分 类 号：P642.4[天文地球—工程地质学]