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为研究岩爆等地质灾害发生的力学机制,利用改进的霍普金森杆试验装置,对红砂岩进行预加载三维静应力下受冲击载荷试验,分析红砂岩的破坏形态、能量耗散规律及变形强度特征.研究表明,红砂岩的破坏形态在有无围压情况下,都随着轴压的增大破坏程度增大,在无围压及有围压情况下分别呈现出“X”型和“圆锥台”型的压剪破坏形态.当轴压固定时,红砂岩的破坏程度随围压的增大而降低.在三维动静组合加载下,红砂岩入射能及单位体积吸收能与平均应变率呈线性递增关系,且递增的程度随轴压的增大表现出先增大后降低的趋势,而随围压的增大而增大.红砂岩应力应变曲线在不同平均应变率下表现出应变回弹、应力跌落及峰后塑性三种类型.红砂岩抗压强度增长因子与平均应变率1/3次幂呈线性递增关系.
In order to study the mechanics mechanism of geological disasters such as rockburst and so on, an improved Hopkinson bar test device was used to test red sandstone subjected to three-dimensional static stress under impact load. The damage morphology, energy dissipation and deformation of red sandstone The results show that the failure state of red sandstone increases with the increase of axial pressure under the condition of no confining pressure, and shows “X” under confining pressure and confining pressure respectively. When the axial compression is fixed, the destructive degree of red sandstone decreases with the increase of confining pressure, and under the combination of three-dimensional dynamic and static loading, the incident energy of red sandstone and the absorption per unit volume Which can be linearly increasing with the average strain rate, and the increasing degree shows a trend of increasing at first and then decreasing with the increase of axial pressure, but increasing with the increase of confining pressure.The stress-strain curve of red sandstone shows the highest average strain rate There are three types of stress resilience, stress drop and post-peak plasticity.The compressive strength growth factor of red sandstone shows a linear increasing relationship with the average strain rate of 1/3 power.