不同层面倾角下锦屏一级水电站左岸板岩坡体破坏模式及能量特征

Failure Modes and Energy Characteristics of Slate on the Left Bank Slope of JinpingⅠ Hydropower Station at Different Dip Angles

为了合理分析锦屏一级水电站左岸坡体的变形,选取坡体板岩进行巴西劈裂试验,分别研究了不同层面倾角下不同饱水率板岩的力学特性及能量特征。结果表明,板岩的抗拉强度随层面倾角的不断增加先减小后增加,其最大降幅达82%;同一层面倾角下,随着饱水程度的增加,板岩抗拉强度逐渐降低,在层面倾角为45°时,抗拉强度从1.64MPa降至0.52MPa,降幅达68%;试样层面倾角0°~90°的破坏受饱水率的影响较小,主要由层面倾角控制,破坏特征分为岩石拉伸型破坏、层面剪切破坏、基质-层面互剪型破坏、层面张拉破坏四种模式;试样破坏的累积能量随饱水程度的增加而不断减小,在相同饱水程度下,累积能量随层面倾角的增大而逐渐减小,累积能量的增长速率与荷载比成非线性关系,在轴向荷载达40%~80%时增长最快。

In order to analyze the deformation of the left bank slope of Jinping Ⅰ Hydropower Station reasonably,this paper selects the slope slate for the splitting test,and studies the mechanical properties and energy characteristics of the slate under different water saturation rates and dip angles.The test results show that the tensile strength of slate decreases first and then increases with the increase of the bedding angle,and the maximum reduction is 82%.Under the same level of inclination,the tensile strength of slate gradually decreases with the increase of water saturation rates.When the inclination angle is 45°,the tensile strength decreases from 1.64 MPa to 0.52 MPa,the decrease of amplitude ratio reaches 68%.Compared with the failure characteristics of the sample layer dip angle from 0°to 90°,it is less affected by the water saturation rates,mainly controlled by the layer inclination angle.The failure characteristics are divided into four modes:rock tensile failure,layer shear failure,matrix-layer mutual shear failure,and layer tensile failure.The cumulative energy of sample damage decreases with increase of water saturation rate.At the same water saturation rate,the cumulative energy gradually decreases as the slope of the layer increases.The growth rate of cumulative energy is nonlinear with the load ratio,and the fastest growth occurs when the axial load reaches 40%-80%.