二维平面波通过节理岩体的传播规律研究

Study on propagation law of two-dimensional plane wave through jointed rock mass

在地下岩体工程中,岩体受到的动态扰动会以应力波的形式传播,并在传播过程中受到岩体内节理等不连续面的影响。为了探究节理空间参数对二维平面应力波在节理岩体中传播规律的影响,将间接波分离法推广至多节理岩体,并采用摆锤式平板试验机开展室内试验。研究结果表明:间接波分离法可用于应力波斜入射多节理岩体的试验结果分析;应力波斜入射角度对反射P波与反射S波的影响显著;量纲一的节理间距的增加对反射P波与透射P波有明显的衰减作用;随着节理交叉角度的增加,交叉节理的S波反射系数和P波透射系数减小,且二者差值逐渐增加。节理交叉角变化时,测点间节理间距的增加对透反射系数的影响显著。研究成果可深化对节理岩体中二维应力波传播规律的认识,并对岩土工程勘探和稳定性分析具有一定的指导意义。

In underground rock mass engineering,the dynamic disturbance propagates in the form of stress wave,and is affected by discontinuities such as joints in rock mass.In order to understand the effect of joint spatial parameters on the propagation of two-dimensional plane stress wave,the indirect stress wave separation method was extended to the case of multi-jointed rock mass,and an indoor experiment was carried out by pendulum plate tester.The results showed that the indirect stress wave separation method could be used to obtain the transmission and reflection characteristics of stress waves in oblique joints and joint sets.The incident angle of the stress wave had a significant effect on the reflected P-wave and the reflected S-wave.The increase of dimensionless joint spacing could reduce the reflection coefficient and transmission coefficient of P-wave obviously.With the increase of the joint intersection angle,the S-wave reflection coefficient and the P-wave transmission coefficient of the intersecting joint decreased,and the difference between the two increased gradually.When the joint crossing angle changed,the influence of joint spacing on the refection and transmission coefficient was dominant.The research results of this paper could deepen the understanding of the two-dimensional stress wave propagation law in jointed rock mass,and have guiding significance for geotechnical exploration and stability analysis of rock mass engineering.