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通过预制裂隙砂浆试件模拟工程实际裂隙岩体,以研究在不同裂隙情况下及有围压作用时裂隙岩体的动力学响应问题。在模具中安装预设裂隙塑料片模拟实际岩层的裂隙倾角及裂隙贯通率,在试验中围压简化为正常金属环固定。基于正交试验方法,利用分离式霍普金森压杆试验装置(split Hopkinson pressure bar,SHPB)研究了不同倾角(0°、30°、45°、60°、90°)、不同贯通率(100%、75%、50%、25%、0%)的砂浆试件在不同围压下的动力学响应。试验结果表明:当倾角小于45°时,试件稳定性随裂隙倾角增大而降低,当倾角大于45°时,稳定性随裂隙倾角增大而提高,倾角45°为稳定性临界点,稳定性与倾角并非线性关系;试件贯通率的增大明显降低动力学强度;施加围压后砂浆试件产生了伪塑性变形,能有效提高动力稳定性,对于高贯通率试件表现尤为明显。该结果为进行地下工程裂隙岩体的强度分析提供参考。
The actual fractured rock mass was simulated by prefabricated mortar specimens to study the dynamic response of fractured rock mass under different fractures and with confining pressure. In the mold, a preset fracture plastic plate is installed to simulate the actual fracture fissure angle and the fracture penetration rate of the rock formation. During the test, the confining pressure is simplified to normal metal ring fixation. Based on the orthogonal experiment method, the effects of different dip angles (0 °, 30 °, 45 °, 60 °, 90 °) and different penetration rates (100 °) were studied by using the split Hopkinson pressure bar (SHPB) %, 75%, 50%, 25%, 0%) mortar specimens under different confining pressures. The experimental results show that when the inclination angle is less than 45 °, the stability of the specimen decreases with the increase of the fracture angle. When the inclination angle is greater than 45 °, the stability increases with the increase of the fracture angle. The inclination angle of 45 ° is the critical point of stability, The relationship between the inclination and the inclination is not linear. The increase of specimen penetration rate obviously reduces the dynamic strength. After the confining pressure is applied, the pseudoplastic deformation of the mortar specimens can be produced, which can effectively improve the dynamic stability. The results provide a reference for the strength analysis of underground engineering fractured rock mass.