排土场散体物料强度对边坡潜在滑动面的影响

高台阶或超高台阶排土场的散体物料块度分布呈现明显的粒径分级特征，物料强度力学特性随块度布组成不同而发生显著变化。通过室内直剪试验揭示排土场散体物料强度参数C、φ与块度组成规律。在此基础上，应用强度折减法，通过对排土场采取逐级分层的方式，研究其强度参数随高度变化时的边坡潜在滑动面及安全系数变化趋势。试验与数值模拟研究表明：其内摩擦角随粗颗粒含量的增多而不断增大，并呈现线性关系；黏聚力呈曲线变化，其总体变化趋势是不断减小的；边坡潜在滑动面随着散体物料分层的不断细分，潜在滑动面出口位置不断向上抬升，塑性区不断向上扩展，最终呈现稳定状态；安全系数随着层数的增加逐渐减小，减小到一定数值（1.125左右）后，随着层数的增加，安全系数又出现一定上升，但变化趋势趋向稳定。

Influence of Strength of the Dump Granular Materials on the Potential Sliding Surface of Slope

High or super-high bench dump′s granular material block size distribution show obvious size grading characteristics，and its strength characteristics vary remarkably with pieces of cloth.The indoor direct shear tests reveal the rule of dump granular material strength parameters C、φ and block composition.On this basis，the strength reduction method is adopted to study the variation trend of the potential slip surface of slope and the safety coefficient at strength parameters varying with the height，through layering the dumps.The experimental research and the numerical simulation show that:the internal friction angle increases with coarse particle content increasing，showing as a linear relationship.Its cohesion varies as a curve，and its overall variation trend becomes more and more slight.The potential slip surface of slope is continuously sub-divided with the granular material layer.The outlet of potential sliding surface is moving upward，and the plastic zone is slightly expanding to be a final steady state; The safety coefficient decreases gradually with the increase of layer number.When the decrease reached a certain value（about 1.125)，the safety coefficient emerges a rising trend，but the trend is becoming stable with the increase of layers number.