摘要
石灰石矿山采场崩塌是藏东昌都地区常见的地质灾害类型,是矿山企业安全生产和铁路工程建设面临的主要地质安全问题之一。文章采用基础地质、构造地质和灾害地质相结合的方法,通过详实的地质灾害调查,查明崩塌发育规律,分析岩体结构面特征,探讨崩塌灾害的形成机理,并建立其破坏模式。结果表明:藏东昌都地区上三叠统石灰石矿山采场崩塌沿区内褶冲带呈线状展布;岩体内发育纵张节理(S_(1))、横张节理(S_(2))、“X”型共轭剪节理(S_(3)、S_(4))及层间剪节理(S_(5))共5组与区域褶皱和对冲系断裂配套的陡倾构造结构面,将岩体切割为破碎的块体;研究区崩塌地质灾害是内、外动力地质作用耦合的产物。晚三叠世(T_(3))早期,昌都地区陆内裂谷盆地环境沉积形成的上三叠统波里拉组(T_(3) b)灰岩是崩塌发育的沉积建造基础;新生代(Cz)印度-欧亚大陆碰撞引发的强烈褶皱造山运动奠定了区内构造格架,是崩塌发育的必要条件;第四纪(Q)以来的强烈新构造运动和晚更新世(Q3)以来的湿-热气候频繁交替、充沛降雨、现代人类活动等做为内和外动力的耦合作用是崩塌灾害的主要诱发因素。研究区内崩塌灾害存在倾倒式、坠落式和滑移式3种破坏模式。研究成果对岩溶区崩塌灾害防治与相关铁路建设具有一定指导意义。
Rockfall in limestone mines is a common geohazard in the Changdu area of eastern Tibet and one of the leading geo-safety issues that mining enterprises and railway projects are faced with.We carried out a detailed geohazard survey using the methods of general geology,structural geology,and geohazard geology.We found the rockfall development pattern,characterized rock mass structural planes,discussed the collapse′s mechanism,and established its failure mode.The results show that rockfall sites in the study area show a linear spreading along the fold and thrust zone.Five groups of steep-dip structural planes have developed in the rock body,including the longitudinal joint(S_(1)),the transverse joint(S_(2)),the X-type conjugate shear joints(S_(3) and S_(4)),and the interlayer shear joint(S_(5)).Paired with regional folds and hedging faults,these structural planes cut the rock mass into broken blocks.The collapses are the product of coupled internal and external dynamic geological processes.The sedimentary foundation of the rockfalls in the Qamdo area is the limestone from the upper Triassic Bolila Formation(T_(3) b)formed in the intracontinental rift basin.The strongly folded orogeny triggered by the Cenozoic(Cz)India-Eurasia collision laid down the tectonic framework in the region,which is the essential condition for rockfall development.The strong Neotectonic movement since the Quaternary(Q),frequent hot and humid climate alternations with abundant rainfall since the Late Pleistocene(Q3),everyday human activities,and other internal and external dynamic coupling effects are the main triggering factors of the rockfall disaster.Three failure modes of rockfall are identified,namely toppling,falling,and sliding.The research results have specific guiding significance for rockfall prevention and control in the karst area and the railway construction in the Sichuan-Tibet area.
作者
李洪梁
高波
张佳佳
田尤
陈龙
黄海
王灵
李宝幸
LI Hongliang;GAO Bo;ZHANG Jiajia;TIAN You;CHEN Long;HUANG Hai;WANG Ling;LI Baoxing(Institute of Exploration Technology,Chinese Academy of Geological Sciences,Chengdu 611734,Sichuan,China;Technology Innovation Center for Risk Prevention and Mitigation of Geohazard,Ministry of Natural Resources,Chengdu 611734,Sichuan,China;College of Earth Sciences,Chengdu University of Technology,Chengdu 610059,Sichuan,China;State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu 610059,Sichuan,China;No.208 Geological Team,Bureau of Geological and Mineral Exploration and Development,Chongqing 401121,China;School of Earth Sciences and Resources,China University of Geosciences(Beijing),Beijing 100083,China)
出处
《地质力学学报》
CSCD
北大核心
2022年第6期995-1011,共17页
Journal of Geomechanics
基金
中国地质调查局项目(DD20221741,DD20190644,DD20190505)
科技部国家重大专项(2019QZKK0902)
国家自然科学基金青年项目(41807300)
西藏自治区自然资源厅项目(藏财采【2020】0890-1)
中国地质科学院探矿工艺研究所科研结余资金项目(2022004)。
关键词
崩塌
内外动力地质作用
形成机理
结构面
褶皱造山运动
水岩交互作用
铁路工程
地质灾害
rockfall
endogenic and exogenic geological processes
formation mechanism
structural plane
fold orogeny
water-rock interaction
railway engineering
geohazards
