折线河岸边坡稳定性的研究

河流水流因素、河岸几何条件、河岸岩土体性质及边坡坡顶裂缝的产生是河岸边坡失稳的重要影响因素。通过建立河岸边坡在临坡水位升降、坡趾淘刷、车辆荷载、偶然作用等多因素影响下失稳的概化理论模型，采用极限平衡法，计算了折线边坡在多因素条件下的边坡抗滑稳定系数。重点分析了临坡河流水位、坡趾淘刷及裂隙水位对于边坡抗滑稳定系数的影响。结果表明：边坡抗滑稳定系数随着临河水位的升高先减小后增大，在这过程中存在一个最不利的水位；同时，随着裂隙水位的增高，边坡抗滑稳定系数逐渐变小；边坡坡趾淘刷对于河岸边坡抗滑稳定性非常不利，随着淘刷高度及切入深度的增大，边坡抗滑稳定系数逐渐变小。

Slope Stability of River Bank with Polygonal Line

Factors including river flow,geometry and rock-soil properties of river bank and cracks at the top of the slope are crucial for the stability of river bank slope.A generalized theoretical model of river bank slope instability under the influences of water level fluctuation,stream erosion at the slope toe,vehicle load and accidental action is established.The model is employed to study the influence of water level fluctuation,stream erosion at the slope toe and hydrostatic pressure on the slope stability of a river bank with polygonal line.With the limit equilibrium method,the slope stability factors under various influences are calculated.Calculation shows that the slope stability factor decreases and then increases with the rise of water level,giving rise to a most unfavorable water level in this rising process.At the same time,the slope stability factor reduces gradually when the fissure water level increases.Moreover,the stability factor declines with the increase of the erosion height and the cutting depth at the slope toe,demonstrating that stream erosion at the slope toe is detrimental to the slope stability.