摘要
白格滑坡发育于金沙江构造混杂岩带,地质条件极其复杂。白格滑坡2018年发生两次大规模滑动后,残留体仍在持续变形,存在再次滑动风险,研究白格滑坡地质结构特征对后续灾害风险评估具有重要意义。基于多年调查结果,结合多期无人机航拍及长期变形监测数据,在查明白格滑坡地质条件基础上,综合分析易滑地质结构、灾变特征及发展趋势。结果表明:滑坡岩体组成及空间分布复杂,主要由片麻岩、千枚岩及蛇纹岩构成,其中蛇纹岩广泛分布于滑坡中上部,易风化崩解,抗剪强度低,是导致滑坡变形的控制性岩性;断裂构造在滑坡区广泛发育,对岩体改造破坏作用显著,促进了滑坡的形成和发展;滑坡存在明显灾后变形现象,残留变形区按空间分布划分为K1、K2及K3区,又进一步细分为具有不同变形趋势的11个子区。其中,K1-1区主要由强风化片麻岩组成,具有高陡临空面,存在突发脆性破坏导致滑坡的可能;K1-4及K1-5分布大量强风化蛇纹岩,深部卸荷变形在第二次滑坡后持续发展,并于2022年11月29日失稳下滑,蛇纹岩山体裂缝仍有不断扩展趋势;K2区变形受炭质板岩及千枚岩控制,变形受降雨影响较大,滑槽临空部位在雨季易产生溜滑破坏;K3区深部岩体较完整,以浅层分解破坏为主,深层滑动可能性小。研究结果可为构造缝合带内的滑坡体地质结构提供工程实践参考。
The Baige landslide is located in the Jinshajiang tectonic melange belt with extremely complex geological conditions.Understanding the geological structure features of the Baige area is of crucial importance for subsequent disaster risk assessment.Following two large-scale landslide events in 2018,certain zones remain in continuous deformation,which may cause further risk of slippage.This study integrated with multi-year investigation,multi-phase UAV digital elevation models,long-term monitoring data,and detailed geological investigation,to comprehensively analyze the facility-sliding geological structure,disaster characteristics,and development trend.The results show that the rock mass composition and spatial distribution of Baige landslide are complex;the landslide body is mainly composed of gneiss,phyllite,and serpentinite.Among these,serpentinite,prone to disintegration and characterized by low shear strength,serves as a key controlling lithology in landslide deformation.The fault structures widely developed in the landslide area also play an important role in the formation and development of landslide.Landslide residual deformation areas can be divided into K1,K2,and K3 according to their spatial distribution,and the three areas can be further subdivided into 11 sub-blocks with different deformation trends.Among them,the K1-1 sub-block has a high and steep surface,while K1-4 and K1-5 contain heavily weathered serpentinite undergoing progressive deep-seated deformation,which culminated in a reactivation event on November 29,2022.The serpentine mountain fissure continues to expand.The K2 area is controlled by carbonaceous slate and phyllite,its damage may be greater in the rainy season.The deep rock mass in the K3 area is relatively complete,with decomposition failure mainly being in the shallow layer and small possibility of deep sliding.The findings provide engineering practical references for the geological structure of landslides within the tectonic melange belt.
作者
张仕林
赵立明
王晨辉
高敬轩
吴新明
王文沛
ZHANG Shilin;ZHAO Liming;WANG Chenhui;GAO Jingxuan;WU Xinming;WANG Wenpei(Faculty of Geosciences and Engineering,Southwest Jiaotong University,Chengdu,Sichuan 610031,China;China Institute of Geo-Environment Monitoring(Guide Center of Prevention Technology for Geo-hazards,MNR),Beijing 100081,China;China Railway First Survey and Design Institute Group Co.Ltd.,Xi’an,Shaanxi 710043,China;Innovation Center of Geological Environment Monitoring Engineering Technology,Ministry of Natural Resources,Baoding,Hebei 071051,China;Faculty of Geological Engineering and Surveying,Chang’an University,Xi’an,Shaanxi 710054,China;Geological Team 915,Sichuan Bureau of Geology and Mineral Resources,Meishan,Sichuan 620020,China)
出处
《水文地质工程地质》
北大核心
2025年第5期160-171,共12页
Hydrogeology & Engineering Geology
基金
国家重点研发项目(2022YFC3004301)
自然资源部地质环境监测工程技术创新中心项目(2022KFK1212005)。
关键词
构造混杂岩带
白格滑坡
地质结构
发展趋势
tectonic melange belt
Baige landslide
geological structure
development trend
作者简介
第一作者:张仕林(1994-),男,博士,讲师,主要从事地质灾害成因方面的研究。E-mail:slzhang@my.swjtu.edu.cn;通讯作者:王文沛(1985-),男,博士,教授级高级工程师,主要从事地质灾害防灾减灾研究。E-mail:jcywangwenpei@mail.cgs.gov.cn。
