Bezie Getaneh, Chala Endalu Tadele, Jilo Nagessa Zerihun, Birhanu Sisay, Berta Kalkidan Kefale, Assefa Siraj Mulugeta, Gissila Biruk
Department of Civil Engineering, Institute of Technology, Dire Dawa University, Dire Dawa, Ethiopia.
Department of Civil Engineering, College of Engineering, Addis Ababa Science and Technology University, Addis Ababa, Ethiopia.
Sci Rep. 2024 Aug 9;14(1):18541. doi: 10.1038/s41598-024-69196-8.
Rock slope failures pose significant challenges in geotechnical engineering due to the intricate nature of rock masses, discontinuities, and various destabilizing factors during and after excavation. In mining industries, such as national cement factories, multi-benched excavation systems are commonly used for quarrying. However, cut slopes are often designed with steep angles to maximize economic benefits, inadvertently neglecting critical slope stability issues. This oversight can lead to slope instability, endangering human lives and property. This study focuses on analyzing the stability of existing quarry cut slopes, estimating their final depth, and conducting a parametric study of geometric profiles including bench height, width, face angle, and rump width. Kinematic analysis helps identify potential failure modes. The results reveal that the existing quarry cut slope is prone to toppling, wedge failure, and planar failure with probabilities of 42.68%, 19.53%, and 14.23%, respectively. Numerical modeling using the finite element method (Phase2 8.0 software) was performed under both static and dynamic loading conditions. The shear reduction factor (SRF) of the existing quarry cut slope was 1.01 under static loading and 0.86 under dynamic loading. Similarly, for the estimated depth, the SRF was 0.82 under static loading and 0.7 under dynamic loading. These values indicate that the slope stability falls significantly below the minimum acceptable SRF, rendering it unstable. The parametric study highlights the face angle of the bench as the most influential parameter in slope stability. By adjusting the bench face angle from 90° to 75°, 70°, and 65°, the SRF increased by 31.6%, 35.4%, and 37.9%, respectively. Among these, a 70° bench face angle is recommended for optimal stability with a SRF of 1.27 under static loading and 1.18 under dynamic loading.
由于岩体的复杂性、不连续性以及开挖过程中和开挖后各种破坏因素的存在，岩质边坡失稳在岩土工程中构成了重大挑战。在采矿业中，如国家水泥厂，多台阶开挖系统常用于采石。然而，为了最大化经济效益，切割边坡通常设计成陡坡，无意中忽略了关键的边坡稳定性问题。这种疏忽可能导致边坡失稳，危及生命和财产安全。本研究着重分析现有采石场切割边坡的稳定性，估算其最终深度，并对包括台阶高度、宽度、坡面角和坡底宽度在内的几何剖面进行参数研究。运动学分析有助于识别潜在的破坏模式。结果表明，现有采石场切割边坡容易发生倾倒、楔形破坏和平面破坏，概率分别为42.68%、19.53%和14.23%。使用有限元方法（Phase2 8.0软件）在静态和动态加载条件下进行了数值模拟。现有采石场切割边坡在静态加载下的抗剪强度折减系数（SRF）为1.01，在动态加载下为0.86。同样，对于估算深度，静态加载下的SRF为0.82，动态加载下为0.7。这些值表明边坡稳定性显著低于可接受的最小SRF，使其处于不稳定状态。参数研究突出了台阶坡面角是边坡稳定性中最具影响力的参数。通过将台阶坡面角从90°调整到75°、70°和65°，SRF分别增加了31.6%、35.4%和37.9%。其中，建议采用70°的台阶坡面角以实现最佳稳定性，静态加载下的SRF为1.27，动态加载下为1.18。
