多层软弱夹层边坡岩体破坏机制与稳定性研究

以大量的实际工程为基础，基于Sarma极限平衡法和有限元强度折减法探讨层状岩质边坡在不同岩层倾角θ、边坡坡角β、结构面间距h条件下的安全系数与破坏面位置的变化规律，揭示复杂多层软弱夹层边坡岩体的破坏机制及稳定性特征。结果表明：不同θ条件下边坡岩体失稳机制和破坏面位置不同，随着θ的增大，破坏机制表现为滑移破坏→滑劈破坏→崩塌破坏→倾倒破坏→滑移破坏；当β、h一定时，直立层状边坡的稳定性略大于水平层状边坡，反倾向边坡的稳定性明显大于顺层边坡；β直接影响边坡岩体破坏特征，当β由30°增大至60°时，顺层边坡的安全系数约降低53%；反倾向层状边坡的安全系数约降低40%；h对边坡岩体破坏机制的影响较小，但对稳定性的影响较大，建议工程实践中加强密集结构面岩质边坡的监测和加固工作。

Research on deformation failure mechanism and stability of slope rock mass containing multi-weak interlayers

Based on many actual projects, through investigating slope rock mass containing multi-weak interlayers with different rock dip angles θ, slope angles β and structural face intervals h, safety factors and the location of critical failure surfaces are calculated by the method of Sarma and strength reduction method. Deformation failure mechanism of slope rock mass containing multi-weak interlayers is studied. The result shows: ①Failure mechanism and failure surface of layered rock slope are greatly different under the condition of different θ, it shows a progress of sliding failure, slip split failure, collapse, toppling failure, sliding failure when θ is increasing. ②As β and h are fixed, the stability of vertical layered slope is slightly larger than that of horizontal layered slope; and anti-dip layered rock slope is obviously larger than bedding rock slope. ③β affects the slope instability and damage features directly, and safety factor of bedding rock slope is reduced by nearly 53% as well as 40% reduction for the safe factor of anti-dip stratified rock. ④Effects of h are minor on slope deformation and failure mechanism but significant on stability, strengthening the monitor and reinforcing dense structure surface rock slope in practice are suggested.