Slope stability analysis and discontinuous slope failure simulation by elasto-plastic smoothed particle hydrodynamics (SPH)
Slope stability analysis and discontinuous slope failure simulation by elasto-plastic smoothed particle hydrodynamics (SPH)
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DOI：
10.1680/geot.9.p.046
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发表时间：
2011-07-01
期刊：
影响因子：
5.8
通讯作者：
Wells, J. C.
中科院分区：
文献类型：
--
作者：
Bui, H. H.;Fukagawa, R.;Wells, J. C.
大多数边坡稳定性分析都采用极限平衡法或有限单元法作为标准方法。然而，边坡失稳往往伴随着土体的不连续破坏，这种破坏既不能用LEMS也不能用有限元来模拟。为了克服这一局限性，本文提出了一种扩展的光滑质点流体动力学(SPH)方法，用于评价边坡的稳定性，并模拟土体的破坏后行为。在边坡稳定性分析中，采用抗剪强度折减法和修正的收敛与非收敛破坏准则来估计边坡的安全系数，并根据累积塑性应变等值线确定临界滑动面。为了考虑孔压的影响，提出了一种新的考虑土体运动的SPH公式。建议将该方程应用于饱和土SPH的进一步发展。作为该方法的应用，给出了几种光滑粒子边坡稳定性分析和相应的边坡破坏模拟，并与其他方法进行了比较。结果表明，在安全系数和临界滑动面方面，计算结果与其他方法吻合较好。然而，与传统方法相比，SPH的一个优点是它可以模拟土体的大变形和破坏后，从而可以处理计算地质力学中的广泛应用，特别是那些包括岩土材料大变形和破坏的应用。
Most slope stability analyses have employed limit equilibrium methods (LEMs) or the finite-element method (FEM) as the standard approach. However, slope instability is often accompanied by discontinuous failure of the soil, which cannot be modelled by either LEMs or FEM. To overcome this limitation, this paper presents an extension of the smoothed particle hydrodynamics (SPH) method to evaluate the stability of a slope, and to simulate the post-failure behaviour of soil. For the slope stability analysis, the shear strength reduction technique with a modified failure criterion for distinguishing convergent from non-convergent solutions is applied to estimate the safety factor of a slope, and the critical slip surface is determined from a contour plot of accumulated plastic strain. To take the pore water pressure into account, a new SPH formulation for soil motion is developed. It is suggested that this equation can be applied to further developments of SPH for saturated soil. As an application of the proposed method, several smoothed particle slope stability analyses and corresponding slope failure simulations are presented, and compared with other solutions. The results show good agreements with other methods in terms of the safety factor and the critical slip surface. As compared with such traditional methods, however, an advantage of SPH is that it can simulate large deformation and post-failure of soil, and can thereby treat a wide range of applications in computational geomechanics, especially those that include large deformation and failure of geomaterials.