Geo-hazards associated with rock slope failures in alpine regions have become increasingly prominent subject to the climate change. Shear behavior of ice-filled rock joints plays an important role in the stability of jointed rock slopes. To explore the shear behavior and failure mechanism of frozen rock joints, granite and sandstone specimens containing a planar joint were prepared. Direct shear tests were conducted on joints with different ice-layer thicknesses based on a novel apparatus designed for testing coupled processes of rock joints. Results show that the aperture of joints (ice-layer thickness) exerts significant influences on the shear strength of ice-filled joints. The cohesive strength of ice-filled joints evolves exponentially with the varying ice-layer thickness and reaches maximum values when the thickness becomes 2–3 mm. Due to the different surface textural properties, the cohesion of the granite joint is more significantly affected by the ice-layer thickness than that of the sandstone joint. The friction angle exhibits a monotonic descending trend and stabilizes when the thickness reaches 4.0 mm. The failure mode of joints with different ice-layer thickness can be categorized into four types: wear and slip of the ice film, fragmentation of the ice layer, debonding of the ice-rock interface, and mixed failure, according to the ice-layer failure characteristics and the strength behavior. The established regression functions taking into account the ice-layer thickness and temperature could serve as basis for mechanical parameter estimation of ice-filled joints.

中文翻译：

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使用新型直剪试验装置进行充冰平面岩石节理剪切行为的基准实验


受气候变化影响，高寒地区岩石边坡崩塌相关的地质灾害变得越来越突出。充冰岩石节理的剪切行为对节理岩质边坡的稳定性起着重要作用。为了探索冻结岩石节理的剪切行为和破坏机制，制备了包含平面节理的花岗岩和砂岩样本。基于一种新型岩石节理耦合过程测试装置，对不同冰层厚度的节理进行了直剪试验。结果表明，节理孔径（冰层厚度）对充冰节理的抗剪强度影响显着。冰填充接缝的内聚强度随着冰层厚度的变化呈指数变化，并在厚度变为 2-3 毫米时达到最大值。由于表面结构性质不同，花岗岩节理的内聚力受冰层厚度的影响比砂岩节理更显着。摩擦角呈现单调下降趋势，并在厚度达到 4.0 mm 时趋于稳定。不同冰层厚度节理的破坏模式按冰层可分为冰膜磨损滑移、冰层破碎、冰岩界面脱粘、混合破坏四种类型失效特征和强度行为。建立的考虑冰层厚度和温度的回归函数可以作为充冰缝力学参数估计的基础。