黄土高原小流域重力侵蚀稳定性评价

为评价黄土高原小流域重力侵蚀稳定性,采用有限差分FLAC3D软件对黄土高原王茂沟小流域概化模型进行了研究。对小流域平衡状态时位移场和应力场和塑性屈服区进行数值模拟,并结合Rosen-blueth矩估计方法对流域重力侵蚀破坏概率可靠度进行了分析。结果表明,剪切塑性区域主要分布于坡面和沟坡大部分区域,张拉塑性区域主要分布于梁峁顶和梁峁坡上部;该流域重力侵蚀处于不可接受的风险水平,需采取有效的工程措施以提高其稳定性。Rosenblueth法可有效地将传统安全系数与概率分布相互结合补充,为建立流域稳定性与重力侵蚀可靠度的指标评价体系提供了一种好的方法。

Stability Evaluation of Gravitational Erosion for Small Watershed on the Loess Plateau

To evaluate the stability of gravitational erosion for small watershed on the Loess Plateau,the conceptual model of Wangmaogou watershed is explored with the aid of the finite difference software,Flac3D,and the numerical simulations for stress field,displacement field and plastic yielded zone are made as the watershed system is in balance.The reliability is analyzed for the failure probability of gravitational erosion,combined with Rosenblueth moment estimation method.Results show that.The shear plastic zone is greatly located in the most area of slope and gully slope,and the tension plastic zone is mainly located on top and slope of barren hill.The gravitational erosion of watershed is in unaccepted risk level and effective engineering measures should be taken to improve its stability.Rosenblueth moment estimation method can effectively combine the conventional safety factor with probability distribution,which may offer a better approach to the building of evaluation index system for watershed stability and gravitational erosion reliability.