岩石高边坡弹塑性平面离散元分析研究

为了更有效指导边坡设计与施工，基于弹塑性平面离散元（DEM）模型，对龙滩水电站航道1+016～1+080段岩石高边坡的开挖支护过程进行了计算分析，分析了边坡在有支护结构对应力场、位移场、整体稳定性和边坡锚索轴力随开挖步骤变化情的影响，同时分析了地下水位升降对边坡变形和整体稳定性变化情况。计算分析结果表明，边坡支护前后，应力场、变形场，塑性屈服区分布情况有明显差别，支护结构可以减小边坡位移，提高边坡整体稳定性，地下水位升降对边坡变形和整体稳定性影响较大。另外，对边坡开挖过程中的坡顶位移和锚杆轴力进行了监测，监测结果与计算结果进行了比较。

Two dimensional elastoplastic distinct element analysis of high rock slope

In order to analyze the anchors supporting structure’s effects, the 1+016-1+080 navigation route bank high rock slope in Longtan Hydropower Station were respectively computed under the supported and un-supported conditions by two-dimensional plane elastoplastic distinct element method(DEM). In the computation, the stress field, deformation field, plastic yielded zones distribution and stability were respectively calculated under supported and un-supported conditions. At the same time, the anchors axial forces during the excavation steps and the groundwater level effects on the slope deformation are also calculated. The analytical results show that there are obvious differences between the supported and un-supported conditions; and the anchors supporting structure can diminish slope deformation and improve the slope stability. Meanwhile, the ground water level of the slope has the obvious effects on the slope’s deformation and stability. The slope top deformation and the anchors’ inner force are measured during the excavation step and there was a good agreement between the DEM computation values and the surveyed values; for example, the max calculated slope top deformation is 9.48cm while the measured values is 7.55cm; and it is shown that the 2D elastoplastic distinct element method is suitable to calculate the high rock slope problems.