边坡开挖对楔型岩块稳定性的影响  

Influence of slope excavation on stability of wedge shaped rock block

作　　者：秦邦民 唐波 张莉萍 许宝田[2] QIN Bangmin;TANG Bo;ZHANG Liping;XU Baotian(Nanjing Water Conservancy Planning and Design Institute Co.,Ltd.,Nanjing 21022,China;School of Earth Science and Engineering,Nanjing University,Nanjing 210046,China)

机构地区：[1]南京市水利规划设计院股份有限公司,江苏南京210022 [2]南京大学地球科学与工程学院,江苏南京210046

出　　处：《江苏水利》2022年第1期5-9,13,共6页Jiangsu Water Resources

基　　金：江苏省水利科技项目(2016054)。

摘　　要：南京秦淮东河铜家山段河道开挖后形成近70 m的高边坡,边坡岩体主要为黄马青组(T 2h)泥质粉砂岩,岩体内发育多组结构面。边坡开挖后其稳定性受结构面组合影响较大,采用离散元法模拟边坡开挖对楔型岩块变形和稳定性影响,模拟分两种情形:(1)结构体为刚体,结构体发生的变形或破坏主要位于结构面上,块体只发生位移或转动,不发生形状和体积的改变;(2)结构体为可变形块体,结构面和块体均可能发生变形或破坏。结果表明,不稳定结构体的滑动在坡面引起较大的变形,特别在结构面位置处有位移值突变现象,如不对坡面块体采取加固措施,则可能引起大范围的岩体破坏;岩块为可变形固体条件下边坡开挖后岩体侧向位移快速增加,岩体发生变形后岩块也可能发生破裂,加速岩体失稳。After the excavation of the Tongjiashan reach of the Qinhuai East River in Nanjing,a high slope of nearly 70m was formed.The rock mass of the slope is mainly argillaceous siltstone of Huangmaqing Formation(T 2h),and multiple groups of structural planes developed in the rock mass.The stability of the slope after excavation is greatly affected by the combination of structural planes.The discrete element method is adopted to simulate the influence of slope excavation on the deformation and stability of wedge-shaped rock block.Based on the engineering geological conditions and the actual situation of slope engineering,there are two schemes for simulation:(1)The structural body is rigid,and the deformation or damage of the structure is mainly located on the structural plane,and the block only undergoes displacement or rotation,and does not change the shape and volume.(2)The structure is a deformable block,and both the structural plane and the block may be deformed or destroyed.The analysis results show that the sliding of the unstable structure causes a large deformation on the slope surface,especially a sudden change in the displacement value at the position of the structural plane.If no reinforcement measures will be taken for the unstable block on the slope surface,it may cause a large-scale of rock mass destruction.Under the condition that the rock mass is a deformable solid,the lateral displacement of the rock mass increases rapidly after the excavation of the slope.After the rock mass is deformed,the rock mass may also fracture,accelerating the instability of the rock mass.

关 键 词：开挖边坡 楔型岩块 变形 稳定性 

分 类 号：TV853[水利工程—水利水电工程]