龙滩电站航道岩石边坡弹塑性平面离散元分析

Two dimensional elastoplastic distinct element analysis of rock slope in navigation route of longtan hydropower station

基于弹塑性平面离散元（DEM）原理，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计算，分析了边坡在有支护与无支护下的应力场、位移场、塑性屈服区和整体稳定性变化情况，同时分析了边坡锚索轴力随开挖步骤变化情况。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，改善边坡屈服区分布，提高边坡整体稳定性；计算值与实测值比较接近，说明计算方法可靠。

By 2D elastic - plastic distinct element method（DEM）, the 1 ＋ 016 - 1 ＋ 080 navigation route bank high rock slope in Long fan hydropower station is computed under the supported and un - supported conditions to analyze the slope supporting structure＇s effects. In the computation, the stress field, the deformation field, the plastic yielded zones distribution and stability are respectively calculated under supported and un- supported conditions. At the same time, the anchors axial force during the excavation steps are also calculated. The analyzed results show that there are obvious differences between the supported and un- supported conditions. The supporting structure can diminish slope deformation, better the plastic yielded zones distribution and improve the slope stability. The slope top deformation and the anchors＇ inner force are measured during the excavation step. There is a good agreement between the DEM computation values and the surveyed values, for example, the max calculated slope top deformation is 9.48 cm while the measured values is 7.55 cm, which suggests this 2D elastic- plastic distinct element method is suitable to calculate the high rock slope problem.