土体受冲击时Rayleigh波作用机制探讨

土体受冲击作用(或称强夯)时Rayleigh波（简称R波）的产生与传播对土体起着不可忽视的作用，重点研究了R波在强夯加固地基中的作用，并结合土体的振动特性，对R波的传播特点、影响深度、引起的变形和体积变化规律进行了讨论。结果表明，R波为强夯法的有效加固波形，其影响深度约为一个波长左右，且对锤底土能起到加密作用，对夯坑以外的土表面在R波的传播过程中有变松作用。结合工程实例给出了成层地基土中R波弥散曲线的求解方法和科学估算强夯影响深度的方法。突破了一直沿用至今的Menard估算加固深度公式的局限。由此可得出，R波在强夯加固地基中有较大的贡献，并非是单纯的有害波的结论。

Discussion on mechanism and effect of Rayleigh wave on soil subjected to impact loading

It is nonnegligible that the Rayleigh wave (R-wave) appearing and transmitting in soil subjected to impact loading (dynamic consolidation in engineering, DC for short). The research on mechanism and effect of R-wave on foundation is made in DC, where the transmitting characteristics，the influenced depth, the laws of deformation and volume variations of R-wave are discussed by means of the vibration characteristics of soil. It turns out that R-wave in DC is effective for the foundation; it is able to influence the depth about one wavelength, and can compact the soil under the hammer. On the other hand, it has some negative effects on the surface of foundation beside the tamping pit. The solving method of dispersion curve of R-wave in the layered foundation and the method of estimating the influenced depth of DC scientifically can be obtained. But Menard’s conventional formula can’t make a precise calculation of the depth. The practical examples are provided to verify the conclusion that DC can benefit more than destructive effect from R-wave.