摘要
陡倾顺层不临空滑坡一般难以提前识别其风险,为揭示此类滑坡演化过程和变形破坏机理,阐明其变形运动特征,以重庆市东阳滑坡为例,在详细地质调查的基础上,选取最不利的地质断面建立理论力学模型、地质模型以及陡倾顺层状岩体溃屈长度方程,并基于有限元方法的数值模型进行模拟分析,结合地质调查及数值模拟综合分析了东阳滑坡的破坏机理、演变过程,分解从滑动到堆积的各阶段特征。研究结果表明:(1)东阳滑坡属于典型的顺层陡倾不临空的岩质斜坡顺层失稳破坏,在长期地下水入渗软化条件下,滑动段重力驱动下,滑体顺层蠕滑至锁固段最终剪切溃屈发生整体滑移破坏;(2)滑坡体演化过程符合岩体结构力学中层状岩体板裂破坏理论,并依据其破坏准则建立溃屈段长度方程;(3)通过FLAC^(3D)软件模拟,滑坡演化过程中水平最大位移的部位发生在滑坡体腰部,纵向最大位移发生在滑体顶部后缘,最大主应力方向在滑坡腰部发生偏转,由平行于主滑面方向向垂直于滑面向外偏转;(4)东阳滑坡运动破坏分解为裂缝发展—滑面贯通阶段、锁固段溃屈—滑体启动阶段、快速滑动阶段、制动堆积阶段4个阶段。
It is generally difficult to identify the risk of steep slope landslides without facing the air in advance.In order to reveal the evolution process and deformation and failure mechanism of such landslides,and clarify their deformation and motion characteristics,this article selects Dongyang landslide in Chongqing as an example,on the basis of the detailed geology survey,select the most unfavorable geological section to establish a theoretical mechanical model,geological model,and the equation for the length of buckling of steeply inclined bedding rock mass.Based on the numerical model of finite element method,simulate and analyze the failure mechanism and evolution process of Dongyang landslide,combined with geological investigation and numerical simulation,decompose the characteristics of each stage from sliding to accumulation.The results show that:①Dongyang landslide is a typical bedding steep slope without air instability failure.Under the long-term softening condition of groundwater infiltration,the sliding body is driven by gravity to creep along the bedding and eventually shear buckling occurs in the locked section.②The evolution process of landslide conforms to the failure theory of lamellar rock mass in rock mass structure mechanics,and the length equation of buckling section is established according to its failure criterion.③Using FLAC^(3D) software to simulate the evolution process of landslides,the maximum horizontal displacement occurs at the waist of the landslide,the maximum longitudinal displacement occurs at the top and rear edge of the landslide,and the maximum principal stress direction deflects at the waist of the landslide,from parallel to the main sliding surface to perpendicular to the sliding surface and outward.④The motion failure of Dongyang landslide can be divided into four stages:crack development and penetration of sliding surface,buckling of locked section and start-up of sliding body,rapid sliding and braking accumulation.
作者
黄浩
余姝
郭健
赵鹏
张枝华
HUANG Hao;YU Shu;GUO Jian;ZHAO Peng;ZHANG Zhi-hua(Chongqing No.208 Geo-environment Research Institute Co.,Ltd.,Chongqing 400041,China)
出处
《煤炭科技》
2023年第5期9-16,共8页
Coal Science & Technology Magazine
基金
重庆市自然科学基金面上项目(CSTB2022NSCQ-MSX1650)。
关键词
顺层滑坡
演化机理
数值模拟
溃屈破坏
bedding landslide
evolution mechanism
numerical simulation
buckling failure
