地下开挖影响边坡稳定性的规律及力学机理

The phenomenon of underground excavation affect the slope stability is common in geotechnical engineerings. To research this affection, the influencing factors of slope stablility of both underground excavation and the slope itself must be taken in consider. This makes the related researches have being taken slowly. As a result, the law and mechanical mechanism about how the underground excavation affect the slope stablility is still not clear. This project is planning to study this affection by simplify this problem to be a simple model, then taking a system research. By taking a series of physcial model tests and numerical model tests on homogeneous slopes with different gradient, different height and differernt materials of diffrerent strength, explore the law and mechanical mechanism about how the slope stability is affected by underground excavation with different positions, different shapes, differernt size, and group effect of multi excavation. This research will enrich the system info of slope stability, and will be helpful for forecasting and controling the related disasters.

岩土工程领域普遍存在着地下开挖影响边坡稳定性的现象。由于同时受到边坡自身和地下开挖两方面多种因素的影响，关于地下开挖对边坡稳定性影响的研究一直进展缓慢，其规律和力学机理都尚不明确。本项研究拟通过一个简化的分析模型对这一问题开展较为系统的研究。针对不同坡度、不同坡高和不同材料强度的二维均质边坡模型，考虑地下开挖的开挖位置、开挖形状和开挖规模，以及多重洞室开挖的群体效应，通过开展物理模型试验和数值模型试验，探索地下开挖影响边坡稳定性的基本规律，明确其力学机理，丰富边坡稳定性的理论体系，为相关灾害的预测和治理提供依据。

针对山岭隧道开挖、矿山露天转井下开采等地下开挖影响边坡稳定性的问题，通过简化的二维均质边坡模型，采用物理模型试验和数值试验的方法，分析了边坡高度、坡角、黏聚力、内摩擦角、开挖区域相对位置、开挖区域距离滑面位置和开挖区域大小对于边坡稳定性的影响。分别探讨了以矢量和安全系数、强度折减安全系数、开挖区域最大位移和开挖后坡面最大水平位移为稳定性评价指标时开挖对边坡稳定性的影响。从试验结果来看，开挖应靠近已知滑面中下部，开挖区域距离滑面不小于1.5倍洞径，这样对边坡稳定性的影响较小。