可控震源粘弹性波动方程有限差分模拟  

Finite difference simulation of viscoelastic wave equation in vibroseis

作　　者：钟飞[1] 张伟[1] 焦标强[2] 钟约先[1] 

机构地区：[1]清华大学机械系教育部先进成形制造重点实验室,北京100084 [2]中国铁道科学研究院机车车辆研究所,北京100081

出　　处：《煤田地质与勘探》2011年第2期57-60,65,共5页Coal Geology & Exploration

基　　金：铁道部-清华基金项目(T200409)

摘　　要：在一般的地震波计算中,地球介质可以当作各向同性的完全弹性体来对待。而对地表土壤和精细观测,粘弹性介质模型比完全弹性模型更符合实际。可控震源是近年来发展起来的精确可控、安全有效的新型震源,但国内对可控震源传播动力学的研究较少。对可控震源激发的地震波在粘弹性介质中的传播,用有限差分方法进行了数值模拟,给出了Kelvin一阶粘弹性波动方程组、吸收边界条件和震源处理。提出了检波器接收信号加速度和传播距离的三次多项式指数关系式,比线性指数关系更准确。使用该公式可以预测采集系统有效接收距离,指导测线布置。Earth can be treated as full elastic isotropic medium in general calculation of seismic wave.Viscoelastic model is more realistic than elastic model for fine observation of surface soil.Vibroseis is a precise,controllable and safe new source developed in recent years.The study of vibroseis transmission dynamics is less mature than pulse source.This article uses finite difference to simulate propagation of seismic wave excited by vibroseis in viscoelastic medium.Kelvin viscoelastic wave equations with absorbing boundary condition and vibration source model are given.The acceleration of received signals and the propagation distance have the cubic polynomial ex-ponential relationship,which is more accurate than the linear exponential relationship,this formula can predict the effective received distance of certain acquisition system.

关 键 词：有限差分 可控震源 粘弹性 正演模拟 

分 类 号：P631.4[天文地球—地质矿产勘探]