某复杂古滑坡堆积体在蓄水条件下的稳定性评价
2016-12-14阚露张发明
阚露+张发明
摘要:文章以位于某水电站坝址区右岸古滑坡Ⅱ区堆积体为研究对象,建立了一个较为复杂的三维模型,并从主应力、塑性区、剪应力和位移四个方面对古滑坡堆积体在蓄水条件下的变形和稳定性情况进行了详细的模拟和分析。计算得到的四个方面的结果都相互吻合相互印证。文章以FLAC3D中的单元界面能自动依附于指定范围内模型表面生成的特性为思路来模拟地下水位。研究结果表明,堆积体虽然未出现整体性滑动破坏,但要注意坡脚局部地区坍塌和土层内部局部滑弧滑动,具体直观地在模型上指出堆积体上的不稳定区域,为后期针对性的加固治理方案提供参考,为工程优化设计提供借鉴意义。
关键词:堆积体;三维数值模拟; 稳定性
中图分类号:文献标志码:A文章编号:1672-1098(2013)03-0000-00
Abstract:This paper studies the deformation and stability of the Ⅱregion of the ancient landslide body on the right bank of a hydropower station by three-dimensional numerical simulation. Detailed simulation and analysis about deformation and stability is realized by the calculation of main stress, plastic zone, shear stress and displacement under water-reserving condition. Results from the four respects confirm each other. The unit interfaces in FLAC3D can attach on the model surfaces at specified areas automatically, which becomes the method to simulate the groundwater level in this article. The finding includes the following. Although there is no whole slip in the calculation, collapse on local areas of the toe of the slope and local circular slide inside the soil layer should be paid attention to. The unstable regions on the slope are pointed out on the slope clearly. References can be presented for the reinforcement method and the optimization design of the project.
Key words:landslide;numerical simulation; stability
崩塌、滑坡发生后形成的堆积体变形及稳定性问题一直是工程地质领域研究的重点问题之一,滑坡形成的堆积体结构松散,强度低,在受到扰动后容易失稳,对水电站的水库正常运营会造成很大的影响,尤其是大型堆积体如果发生破坏,很可能会堵塞河道,后果不堪设想。迄今为止,研究者们已提出了如极限平衡分析法、块体理论法[1]、数值方法[2-3]等计算条件相对简单的传统方法,也提出了人工神经网络理论[4]、模糊数学理论[5]、灰色系统理论[6]、可靠性理论[7]等基于未确知性理论的计算方法。
本文采用FLAC3D数值模拟的方法对某水电站坝址区右岸古滑坡Ⅱ区堆积体进行稳定性分析, 由于FLAC3D采用的是显式差分法求解微分方程,不形成刚度矩阵,每一步计算仅需要很小的内存。……
