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基于改进的分离式霍普金森压杆(SHPB)岩石动静组合加载试验系统,进行了在不同静力轴压条件下受频繁动力扰动作用的动力学试验,研究蛇纹岩在高静载下受频繁冲击扰动过程中的动态变形特性、动态峰值应力和应变、能量变化规律和岩石破坏模式等动力学特性。研究结果表明:高静载条件下受频繁冲击扰动作用时,在动态峰值应力前,动态应力与应变呈正相关关系,而在动态峰值应力后,出现变形回弹和不回弹两种现象;随着动力扰动次数的增加,岩石动态峰值应力减小、动态峰值应变增大、动态变形模量减小、岩石由释放能量向吸收能量方向转化;随着预加静力轴压的增大,单次冲击过程中岩石损伤加剧,岩石破坏需要的扰动冲击次数减少,同时岩石由拉伸破坏模式向压剪破坏模式转变,破坏块度由小变大、均匀度降低。试验结果对揭示深部岩体承受高地应力和频繁开挖爆破等动力扰动作用下的破坏机制具有重要意义,同时为工程实际中通过调整围岩静应力状态和爆破以提高围岩长期稳定性的可行性提供了室内试验支持。
Based on the improved split Hopkinson pressure bar (SHPB) rock dynamic and static loading test system, dynamic tests under frequent hydrodynamic perturbations under different static axial compressions were carried out to study the influence of frequent shocks Dynamic deformation during disturbance, dynamic peak stress and strain, energy variation and rock failure modes. The results show that there is a positive correlation between dynamic stress and strain before dynamic peak stress under the condition of frequent impact disturbance under high static load condition. However, after dynamic peak stress, both deformation and non-rebound phenomena occur. With the increase of disturbance frequency, the dynamic peak stress decreases, the dynamic peak strain increases, the dynamic deformation modulus decreases, and the rocks transform from the released energy to the absorbed energy. With the increase of the prestatic axial pressure, the single impact During the process, the rock damage is aggravated, and the number of disturbance impacts required by rock failure is reduced. At the same time, the rock changes from tensile failure mode to compression failure mode, and the failure degree increases from small to small, and the uniformity decreases. The test results are of great significance for revealing the failure mechanism of deep rock mass subjected to dynamic stress such as high ground stress and frequent excavation blasting. At the same time, it is feasible to improve the long-term stability of surrounding rock by adjusting the static stress state and blasting of surrounding rock in engineering practice Sex provides in-house test support.