基于FLAC3D的某水电站岩体倾倒变形过程数值模拟研究

Numerical Simulation Study on the Toppling Deformation Process of Rock Mass in a Hydropower Station Based on FLAC3D

我国西南高山峡谷地区地质作用强烈,倾倒变形岩体广泛发育,基于拉格朗日有限差分法的FLAC3D软件可对岩体倾倒变形过程进行数值模拟研究。建立了流变模型对澜沧江上游某在建水电站的一处倾倒变形体进行了研究,结果表明,在岩体自重和卸荷应力的长久作用下,库区陡立岩层会朝向临空位置发生倾倒变形破坏。这是一个长期的流变破坏过程。倾倒变形仅发育在边坡的浅表层,深部的岩体未发生倾倒,浅表层底部的岩层弯曲最为强烈,这些部位的岩层将最先发生折断,若折断面贯通,极有可能导致倾倒体整体垮塌滑动引发滑坡等灾害。在水电站建设中要着重考虑对倾倒变形程度严重的坡体进行支护,防止发生大规模的失稳破坏。

The geological processes in the mountainous and canyon areas of southwestern China are strong,and the tilted and deformed rock masses are widely developed.The FLAC3D software based on the Lagrangian finite difference method can conduct numerical simulation research on the process of rock mass toppling deformation.This article establishes a rheological model to study the toppling deformation of a hydropower station under construction in the upper reaches of the Lancang River.The results indicate that under the long-term action of the self weight and unloading stress of the rock mass,the steep rock layers in the reservoir area will tilt and deform towards the vacant position.This is a long-term rheological failure process.The tilting deformation only develops in the shallow surface of the slope,and the deep rock mass does not experience tilting.The rock layers at the bottom of the shallow layer bend the most strongly,and the rock layers in these areas will be the first to break.If the broken section is connected,it is highly likely to cause the overall collapse and sliding of the toppling body,leading to disasters such as landslides.In the construction of hydropower stations,it is important to focus on supporting slopes with severe tilting deformation to prevent large-scale instability and damage.