节理岩石的应力波动与能量耗散

应用SHPB试验和分形方法研究节理岩石的应力波动与能量耗散关系，分析节理面不规则结构对应力波穿越节理时的波动性质、非弹性变形和能量耗散的影响。研究结果表明：节理面不规则结构明显地影响应力波的传播性质。在相同入射波条件下，粗糙节理岩样的应力波衰减程度大于平直光滑节理岩样的衰减程度，粗糙节理的实际变形大于平直节理的变形。节理岩石的能量耗散比WJ/WI随节理面分维值D增大而增加，两者呈非线性关系；但当分维值小于临界值时，粗糙节理岩样的能量耗散比WJ/W与平直节理面的能量耗散比基本相同，并给出节理岩石能量耗散随节理面分维值D变化的表达式。

STRESS WAVE PROPAGATION AND ENERGY DISSIPATION IN JOINTED ROCKS

The stress wave propagation and energy dissipation in jointed rocks are investigated by split Hopkinson pressure bar(SHPB)technique and fractal theory.The influence of the irregular geometrical configuration of the joint surface on the wave propagation,inelastic deformation and energy dissipation has been analyzed.It is shown that the irregularity of the joint surface apparently affects the stress wave transmission.With the same incident pulses,the amplitude of stress wave was attenuated seriously when it traveled through the rough fractal joint compared with the smooth plane joint.The deformation of a rough fractal joint was found to be larger than that of a smooth plane joint.The ratio of energy dissipation WJ/WI increases nonlinearly with increment of fractal dimension D of the jointed surface.Nevertheless,the energy dissipation ratio WJ/WI of the roughly jointed rocks seems to be the same as that of the smoothly jointed rocks if the fractal dimension of the joint surface is less than the critical value.An empirical model for energy dissipation ratio to the fractal dimension of joint surface has been formulated.