典型含煤模型Love型槽波的频散特征分析

为了研究不同地质条件下煤层Love型槽波的频散特征，设计了4种典型二维地震地质模型，即围岩不变而煤厚变化（3，5，10，15和20 m）模型，围岩变化（高速围岩与低速围岩）而煤厚不变（10 m）模型，煤层含有断层（煤厚10 m、断层落差5 m）模型和10 m煤层中夹有5 m×5 m、5 m×10 m、5 m×20 m、5 m×50 m砂体模型等；采用SH波波动方程，对上述模型进行了数值模拟，分析了Love型槽波的波场特征，并对正演记录进行了傅里叶变换，计算得到槽波频散图。结果表明：煤厚变化主要影响Love型槽波各阶模式频散曲线的能量分布，上下围岩中最小横波速度控制频散曲线的上限，砂体使频散曲线发散，断层对槽波频散影响较小。

Love channel-waves dispersion characteristic analysis of typical coal models

In order to study the dispersion characteristics of Love channel-waves under different geological conditions,four kinds models of 2D typical seismogeology were designed.There are various coal thickness models,different wall rock(high-velocity and low-velocity wall rock models)for which the coal thickness is stable as 10 m,coal models containing 5 m fault for which the coal thickness is 10 m,and coal imbedded by leat which sizes are 5 m×5 m,5 m×10 m,5 m×20 m and 5 m×50 m.These models were numerically simulated by SH wave equation.Analyzed the wave-fields characteristics of Love channel-waves and used Fourier transform on synthetic seismic records to obtain channel-waves dispersion curves;the results show that the coal thickness mainly influences energy distribution of different modes’ dispersion curves.The minimum shear wave velocity between top and bottom wall rock controls upper limit of dispersion curves;leat bodies make dispersion curves diffuse.The fault has a low impact on channel-waves dispersion.