基于物理模型试验的含多层软弱夹层顺层开挖高边坡变形破坏特征分析

含有多层软弱夹层的开挖边坡具有坡体结构复杂、稳定性评价及治理难度大的特点。以黔西地区现场开挖高边坡为研究对象，建立室内物理试验模型，通过不同的工况开挖，呈现变形破坏演化过程，分析变形破坏模型及形成机理，确定失稳破坏范围。结果显示:开挖边坡裂隙产生由表及里，由上及下，由最初的陡倾短小裂隙扩展延伸，最终贯通，形成近似平行岩层的长大裂缝；缓坡度开挖变形破坏为浅表层，整体稳定性较好，失稳范围及规模较小；陡坡度开挖变形破坏规模大，稳定性较差，以滑移-拉裂深层失稳为主；浅层滑坡滑面以层间泥化夹层剪切为主，基本呈直线状；深层滑坡滑面以层间泥化夹层剪切以及陡倾裂隙组合形成阶梯状。该研究成果对于黔西地区的顺层开挖高边坡设计、稳定性评价、治理措施选择等具有重要的指导意义。

Analysis on deformation characteristics of a cutting high bedding rock slope with multiple weak layers based on physical model tests

The excavated slope with multi-layer weak interlayer has the characteristics of complex slope structure and difficult stability evaluation and treatment. Based on the on-site excavation of high slope in western Guizhou, an indoor physical test model is carried out. Through excavation under different working conditions, the evolution process of deformation and failure is presented. The deformation and failure model and formation mechanism are analyzed to determine the instability and failure range. The results show that the fissures in the excavated slope extend from the surface to the inside, from top to bottom, from the initial steep short fissures, and finally through to form a long fissure approximately parallel to the rock layer; the deformation and failure of gentle slope excavation is shallow surface, the overall stability is good, and the instability range and scale are small; the excavation deformation and failure scale of steep slope is large, and the stability is poor, mainly in the deep instability of slip tensile fissure; the slip surface of shallow landslide is mainly sheared by interlayer argillaceous interlayer, which is basically linear; the sliding surface of deep landslide is stepped by the combination of interlayer argillaceous interlayer shear and steep inclined fractures. The research results have important guiding significance for the design, stability evaluation and treatment measures of bedding excavation high slope in western Guizhou.