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在弹性介质假定和忽略反射波影响的条件下,从透射波振幅和能量的角度,研究了SH波入射时入射角与波阻比对软弱夹层减震特性的影响。通过非线性弹塑性动力计算,探讨了软弱夹层的埋深与层厚对其减震特性的影响。研究结果表明,随着入射角的增大,透过软弱夹层进入上部普通层的波的振幅和能量先缓慢增大至与入射波相同,然后快速减小至0,整体上小于入射波;存在最不利入射角,它是波速比与密度比的函数,当SH波以此角度入射时,夹层的底面和顶面均不存在反射波,入射波全部透过夹层;软弱夹层与普通层的波阻比越小,透过夹层进入普通层的波的振幅和能量越低,夹层的减震效果越好,但此时夹层自身的震动也越剧烈。随着入射波波长的增加,软弱夹层发挥减震作用所需的临界埋深增大,且埋深在0.2倍普通层剪切波波长左右时,减震效果达到最佳;软弱夹层的减震效果并不随着层厚增加单调变化。
Under the assumption of elastic medium and ignoring the effect of reflected wave, the influence of incident angle and wave resistivity on the shock absorption characteristics of soft interlayer is studied from the angle of transmitted wave amplitude and energy. Through the nonlinear elasto-plastic dynamic calculation, the influence of the depth and layer thickness of soft interlayer on its shock absorption characteristics is discussed. The results show that as the incident angle increases, the amplitude and energy of the wave entering the upper common layer through the weak interlayer slowly increases to the same as the incident wave and then decreases rapidly to 0, which is smaller than the incident wave as a whole. The most unfavorable angle of incidence, which is a function of wave velocity ratio and density. When the SH wave is incident at this angle, there is no reflected wave on the bottom surface and the top surface of the interlayer, and all the incident waves are transmitted through the interlayer. The smaller the resistance ratio, the lower the amplitude and energy of the waves entering the normal layer through the interlayer, the better the damping effect of the interlayer, but at this moment, the more severe the vibration of the interlayer itself is. As the wavelength of incident wave increases, the critical depth of weak interlayers for damping effect increases, and the damping effect reaches the best when the buried depth is about 0.2 times the wavelength of ordinary shear wave. The damping of weak interbed The effect does not increase monotonically with layer thickness.