摘要
现有的微震源定位方法假设地震波沿直线传播,定位结果往往不能满足精度要求,为此建立一种新的微震源快速定位方法--地震波最小走时面法。该方法考虑波的传播符合斯涅尔定律而提出地震波最小走时路径射线传播平面的假设,通过旋转坐标系,将地震波三维传播路径转换为二维平面传播路径,实现平行分层岩体中相对准确的地震波初至到时计算,并在三层水平模型中采用改进的遗传算法进行微震源的优化求解验证假设的有效性,同时对影响定位精度的因素进行分析。结果表明,最小走时面法所得地震波走时明显优于传统最短几何路径走时计算方法,二者的差值是微震源和传感器连线倾角α和间距L的函数;该算法在多层岩体的微震源定位中具有良好的定位精度,且不受介质波速比的影响。
The existing microseismic source location methods assume that the seismic wave propagates along straight lines,and the positioning results often fail to meet the accuracy requirements.In this paper,a new location method of microseismic source named as minimum travel time surface method of seismic wave was established.This method considers Snell's law of seismic wave propagation and assumes seismic wave minimum travel path ray propagation plane.By rotating the coordinate system,the three-dimensional propagation path of seismic waves can be transformed into a two-dimensional plane propagation path,and the relatively accurate calculation of initial arrival and travel time of micro-earthquakes in parallel layered rock mass can be realized.The improved genetic algorithm was used to optimize the microseismic source in the three-layer horizontal model to verify the validity of the hypothesis,and the factors affecting the positioning accuracy were analyzed.The results show that the travel time obtained by the minimum travel time surface method is significantly better than that obtained by the traditional shortest geometric path travel time calculation method,and that the difference between them is a function of the inclinationa and the distance L of the connection line between the microseismic source and the sensor.The new location method has a great positioning accuracy in multi-layer media and the positioning accuracy is not affected by the wave velocity ratio of the medium.
作者
徐港
薛传荣
王鑫科
高德军
XU Gang;XUE Chuanrong;WANG Xinke;GAO Dejun(College of Civil Engineering and Architecture,China Three Gorges University,Yichang,Hubei 443002,China;Hubei Key Laboratory of Disaster Prevention and Mitigation,China Three Gorges University,Yichang,Hubei 443002,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2021年第8期1654-1663,共10页
Chinese Journal of Rock Mechanics and Engineering
基金
国家重点研发计划资助项目(2017YFC1501100)
三峡大学学位论文培优基金项目(2020SSPY016)。
关键词
岩石力学
三维层状岩体
微震源定位
最小走时面
遗传算法
rock mechanics
3-D layered rock mass
microseismic source localization
minimum travel time surface
genetic algorithm
