某水电站2#倾倒体时效变形及失稳模式的离散元分析  

Discrete Element Simulation Analysis of Time-dependent Deformation and Failure Mode of 2# Toppling Slope of a Hydropower Station

作　　者：杨彦军 邱俊 张一军 王云南 YANG Yanjun;QIU Jun;ZHANG Yijun;WANG Yunnan(SCIVIC Engineering Corporation,Luoyang,Henan 471003,China;Longchang Natural Resources and Planning Bureau,Longchang,Sichuan 642150,China;China Jikan Research Institule of Engineering Imwestigations and Design,Co.,Ld.,Xi'an,Shaanxi 710021,China;Jiangxi Seience&Technology Normal University,Nanchang,Jiangxi 330013,China)

机构地区：[1]机械工业第四设计研究院有限公司,河南洛阳471003 [2]隆昌市自然资源和规划局,四川隆昌642150 [3]机械工业勘察设计研究院有限公司,陕西西安710021 [4]江西科技师范大学,江西南昌330013

出　　处：《水利与建筑工程学报》2024年第3期48-57,共10页Journal of Water Resources and Architectural Engineering

基　　金：地质三维模型在建筑地基基础设计及施工中的应用(2022XJZD010)

摘　　要：为深入研究倾倒体变形破坏全过程特征,以某水电站消力塘左岸2#倾倒体为例,在野外调查基础上,利用离散元模拟,从模型时效变形及变形机理出发,分析该倾倒边坡在现状及地震作用下的失稳模式。结果表明:当边坡变形累积到一定程度,不稳定地质体将发生失稳,其位移表现为宏观的快速增加,若地质体的失稳是强震触发的,其位移还具有一定的“震荡”特征;倾倒边坡前期或前中期的变形破坏以沿结构面的剪切错动为主导,之后,随着拉张效应的逐渐积累,变形转为以沿结构面的拉张破裂为主;地震作用下,边坡中质点的水平速度及加速度均有高程放大效应,其中加速度放大系数大于速度放大系数,边坡破坏时,由于动力波的加速效应及岩体弹性应变能的释放将获得较大的水平加速度,表明岩体中的弱面对于岩质边坡的稳定性起控制作用;现状条件下,2#倾倒体整体稳定,其失稳模式以浅表层岩体的局部垮塌或沿小型山脊的滑塌为主,而遭受地震时则有整体失稳的可能,若整体失稳,其失稳过程应为:表层松动岩体率先垮塌、滚落→坡体震裂松弛→形成“滑移-拉裂”型滑坡。In order to thoroughly analyze the deformation and failure characteristics of toppling Slope, this work took the 2# toppling slope in the left bank of a hydropower station stilling basin as an example, the discrete element numerical simulation is carried out to analysis the time-dependent deformation and its deformation mechanism based on field survey, and the failure mode under the earthquake action or the current situation was also analyzed. The results are as follows. The deformation and failure of a slope is a progressive process from quantitative change to qualitative change, in this case, the unstable geological body will fail when progresses a certain degree, resulting in the displacement increase rapidly, and the displacement has some certain shock characteristics if triggered by earthquake. The previous or prometaphase deformation and failure of a toppling slope is dominated by the structure′s shear moving. With the gradually accumulated of tension effects, the deformation is mainly controlled by tensile rupture. Horizontal velocity and acceleration of the particle in slope have the elevation amplification effect under earthquake action, and the acceleration amplification coefficient is greater than the speed′s, and slope will get a big horizontal acceleration due to the acceleration effect of power wave and the release of elastic strain energy of rock mass when it destroys, which indicates the weak structural plane of rock mass controls the stability of rock slope. At present, 2# toppling slope is in a stable state as a whole, and its failure mode gives priority to the local collapse or the sliding along a small ridge on surface, but it may get entire failure when suffered from earthquake, in that case, the failure process should be the surface first to collapse and tumble, the slope shakes to loose, finally form a type of "sliding-tension" landslide.

关 键 词：层状边坡 倾倒变形 失稳模式 离散元分析 

分 类 号：P642[天文地球—工程地质学]