基于DDA的强度折减法求土坡安全系数

介绍了非连续变形分析(DDA)方法和强度折减法的基本理论,提出了基于DDA的强度折减法求土坡安全系数的方法。分析了在计算连续介质时块体的划分方法,提出应预先根据费伦纽斯经验方法假定土坡潜在滑动面的位置和形状,依据强度折减法,分别求出各条滑动面在失稳破坏时的折减系数,即为此条滑动面的安全系数。然后绘曲线找出最小值,即为土坡的稳定安全系数。提出了DDA法判定土坡失稳破坏的标准,通过算例证明了此法在计算土坡稳定安全系数时的可行性,所得到的安全系数较其他几种方法偏小。

Calculating Safety Factors of Soil Slope Stability with Strength Reduction Method Based on DDA

The general principle of DDA,discontinuous deformation analysis,and the shear strength reduction are discussed simply.The shear strength reduction method based on DDA is proposed.The way of compartmentalizing the continuous medium is analyzed.And assuming the location and shape of potential slip surface beforehand based on the Fellenius thumb rule is proposed.With the shear strength reduced,the reduction factor when the stability failed for every assumed slip surface are calculated,and the minimum reduction factor is found out,the safety factor of the soil slope is then obtained.A criterion,which is used to distinguish the collapse of slope,is proposed.The feasibility of the shear strength reduction DDA method on calculating the safety factor of soil slope is illustrated,but the safety factor is less than other methods.