岩质斜坡锁固段破坏模式的物理模型试验研究

Study on Failure Modes of Various Locked Segments in Rock Slopes Based on Physical Model Tests

大型岩质斜坡的稳定性常受潜在滑面上的锁固段所控制,理解锁固段破坏机理是解决岩质锁固型斜坡失稳预测问题的关键。基于已有的岩质锁固型斜坡分类,对每一类斜坡锁固段破坏模式进行了物理模型试验研究。结果表明:跨层斜切式斜坡的锁固段破坏模式为拉剪破坏;顺层直剪式斜坡靠近坡脚临空面处的下部锁固段首先发生拉剪破坏,随之上部锁固段发生剪切破坏;均质岩桥式锁固段破坏模式为拉剪破坏,而挡墙式锁固段破坏模式为剪切破坏。

The stability of large-scale rock slopes is essentially controlled by the internal locked segments along the potential sliding surface.Therefore,better understanding of the failure mechanism of locked segments is crucial to the successful prediction of instability of such rock slopes.In this paper,several physical model tests are performed to investigate the failure modes of four types of locked segments based on the available classifications of rock slopes with locked segments.Experimental results show that the failure mode of the locked segment in a cross-layer miscut slope is tensile-shear.For the bedding slip slope,the locked segment rupture near the toe of the slope behaves in a tensile-shear mode,which then leads to a shear failure of the locked segment at the top of the slope instantaneously.The failure modes of the locked segment like a homogeneous bridge and the locked segment like a retaining wall are tensile-shear and shear,respectively.