层状岩质边坡遍布节理模型的三维稳定性分析

采用遍布节理模型（ubiquitous-joint模型）描述层状岩体的各向异性特征，并探讨ubiquitous-joint准则中安全系数的计算方法，利用FLAC3D分析层理倾角、倾向与边坡稳定性之间的关系，结果表明：（1）对于顺层边坡，当岩层倾向与坡面倾向的夹角 较小时，边坡的安全系数随层理倾角 的增大呈现先减小后增大再减小的趋势； 20°～30°时，安全系数得到最小值， 60°时安全系数得到最大值；不同破坏型式导致安全系数变化规律之间的差异；当 较大时，曲线从先减小后增大的趋势转变为不断增大的趋势；根据 的大小将顺层边坡分为两类：当 45°时，为严格顺层边坡；当45° 90°时，为斜向层状边坡。（2）对于逆层边坡，当 45°时，曲线呈现先增大再减小然后又增大的趋势，各曲线随 的变化程度基本相同；但减小过程中，随着 的增大，曲线的斜率逐渐减小，边坡稳定性的各向异性程度减小；当 45°时，曲线随 的增大呈现非线性单调递增的趋势。（3）安全系数与 之间的关系表明，对于顺层坡，随着 的增大，边坡安全系数逐渐增大；对于逆层坡，当 较小时( 150°)，边坡安全系数随 的增大而逐渐减小；随着 的增大( 120°)，边坡安全系数与 呈现递增关系。

Three-dimensional stability analysis of stratified rock slope based on ubiquitous-joint model

The anisotropic characteristics of stratified rock mass are described by ubiquitous-joint model; the calculation method of safety factor based on ubiquitous-joint model is proposed; then the relationships between stratification dip angle , inclination and slope stability are analyzed by FLAC3D. The results show that (1) for bedding rock slope, when the angle between inclination of slope and rock stratum is small, the slope safety factor decreases, increases and then decreases with the increase of ; when 20－30°, the safety factor reaches the minimum value; while 60°, it reaches maximum value; different failure modes cause the variations of safety factor; when is large, the relationship curve shows the decrease then increase trend to gradually increase; according to the value of , the stratified rock slope can be divided into two types: 45° for strict bedding rock slope; 45° 90°for oblique stratified slope; (2) for reverse layered slope, when 45°, the relationship curve shows the trend of increase, decrease and then increase; the variation degree of each curve is almost the same with the variations of ; during decrease process, the slope of curve decreases gradually with the increase of , and the anisotropic characteristics of slope safety factor become small; when 45°, the relationship curve shows the trend of monotone increasing in nonlinear form; (3) the relationship between slope safety factor and shows that for bedding rock slope, the safety factor increases with the increase of ; for reverse layered slope, when is small ( 150°), the slope safety factor decreases with the increase of ; and with the increase of ( 120°), the slope safety factor increases while increases.