含流体孔隙介质中勒夫面波衰减特性及其表征方法研究

项目名称： 含流体孔隙介质中勒夫面波衰减特性及其表征方法研究

项目编号： No.41304077

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 天文学、地球科学

项目作者： 张煜

作者单位： 武汉大学

项目金额： 25万元

中文摘要： 地震波的衰减特性对地下介质的变化较波速敏感，反映了地下介质的动力学特征，是目前地震探测方法关注的热点问题。本课题拟针对近地表普遍含流体的水文地质特征，利用可较好预测体波在地震观测频带内衰减特性的提升Biot多相含流体孔隙介质模型，结合含流体的边界条件，通过理论分析、数值模拟和岩石物理实验，研究勒夫面波在斑块饱和（PS）、双孔隙（DP）和多相饱和（MS）模型中的衰减特性及其与剪切波传播的内在联系；并探讨在实际观测的条件下，用粘弹性等效描述面波衰减特性的理论、方法、条件以及相应的精度；在此基础上进一步给出定量的等效表征模型对近地表剪切波速度和衰减时间频率响应特征的约束条件。研究成果将为建立顾及衰减物理机制的面波动力学方法提供理论支撑和线索，推动地震探测技术的发展。

中文关键词： 面波；孔隙介质；流体；衰减；模拟

英文摘要： Attenuation characteristics of seismic waves are more sensitive than wave velocities to the changes of subsurface earth media, and can represent the dynamic features of earthe media, which is now the focus in the field of seismic detections. For the universal near surface fluid-filled hydrogeologic conditions, the aim of this research intends to research the attenuation characteristics of Love waves in patchy saturation, double porosity and multiphase saturation porous models, of the upscale Biot fluid-filled porous models which can well predict the attenuation charaterisctics of the body waves in seismic exploration frequency band, with different fluid boundary conditions, and the inherent relationships to the propagations of the shear wave. Moreover, we propose to investigate the theory, method, condition and accuracy to apply the viscoelastic effective equivalent representations for the attenuation characteristics of Love waves on the basis of the actual observations. Further more, we will preliminarily use the equivalent attenuation representations to constrain the velocity and attenuation time and frequency responses in the inversion model. The research will provide theoretical support and clues for the establishment of surface wave dynamic method considering attenuation physical mechanisms,and also promote

英文关键词： surface wave；porous media；fluid；attenuation；modeling