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对瑞利波勘探中“之”字形频散曲线形成的物理机理进行了理论分析，研究了诸波模的传播特性及相互关系．指出在地表下存在具有水平界面的软弱夹层和地层裂缝时，瑞利波频散曲线中的“之”字形结构是低速夹层或地层裂缝中出现多模现象的结果．利用阻尼最小二乘法和遗传算法对瑞利波频散曲线反演介质参数进行了研究和分析，发现最小二乘法不适合瑞利波“之”字形反演问题研究，而用遗传算法得到了较好的结果．
The physical mechanism of the formation of “zigzag” dispersion curve in Rayleigh wave exploration is theoretically analyzed, and the propagation characteristics and interrelations of the wave modes are studied. It is pointed out that the “zigzag” structure in the Rayleigh wave dispersion curve is the result of multimode phenomenon in low-velocity interbeds and formation fractures when there are weak intercalations and formation fractures with horizontal interfaces under the surface. Damping least square method and genetic algorithm were used to study and analyze the medium parameters of Rayleigh wave dispersion curve inversion. It was found that the least square method is not suitable for the study of Rayleigh “zigzag” inversion problem, but the genetic algorithm good result.