Preliminary study on landslides of the anti-dip layered rock slope under the action of normal faults
正断层作用下逆倾层状岩质边坡滑坡初步研究

摘要

随着露天煤矿开采深度增加，断层影响下的逆倾层状岩质边坡稳定性问题日益突出。本文以霍林郭勒古城露天煤矿为工程背景，针对正断层FD1作用下的高陡逆倾边坡，采用MatDEM离散元数值模拟方法，开展滑坡破坏机制研究。通过构建含正断层的边坡细观模型，结合室内试验数据对泥岩、粉砂岩、褐煤等多类岩层材料进行微观参数标定，并开展重力作用下的动态演化模拟。研究结果表明：在正断层与逆倾层状结构共同作用下，边坡失稳呈现典型的顺层-切层复合滑动模式，滑动面沿断层上盘弱面起裂，并沿煤层底板软弱界面扩展，形成“头大尾小”的整体滑坡形态。该破坏机制揭示了正断层通过扰动应力场和提供滑移通道显著降低边坡稳定性的作用机理。研究成果为复杂地质条件下露天矿边坡稳定性评价与灾害防控提供了理论依据和实践参考。

Abstract

With the increasing mining depth of open-pit coal operations, the stability of reverse-inclined layered rock slopes affected by faults has become an increasingly critical issue. Taking the Huolinguole Ancient City open-pit coal mine as the engineering background, this study investigates the landslide failure mechanism of high and steep reverse slopes influenced by the normal fault FD1 using the MatDEM discrete element numerical simulation method. A microscale slope model containing a normal fault was constructed and calibrated based on laboratory test data for mudstone, siltstone, and lignite to obtain the corresponding microscopic parameters. Dynamic evolution simulations under self-gravity were then conducted. The results show that under the combined influence of normal faults and reverse-inclined stratified structures, slope instability typically manifests as a bedding-shear composite sliding mode. The failure surface initiates along the weak plane of the hanging wall of the fault and propagates along the weak interface at the coal seam floor, forming an overall “large-head and small-tail” landslide morphology. This failure mechanism reveals how normal faults significantly weaken slope stability by disturbing the stress field and providing preferential slip pathways. The findings offer valuable theoretical guidance and practical reference for slope stability evaluation and disaster prevention in open-pit coal mines under complex geological conditions.