微震初至波在岩层中的传播路径研究
Study on Spreading Route of Micro-Seismic Initial Arrival Wave in Rock Strata
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摘要: 为了合理解释微震初至波在岩层中传播路径,提高微震监测系统的监测精度,从现场微震波传播异常现象出发,利用地震波基础理论,分别以微震初至波在单一岩层和过岩层分界面的传播方式及路径建立了模型,着重分析了过岩层分界面时,震源与拾震器位于同一岩层中以及位于不同岩层中微震初至波的传播路径。在此基础上,优化了微震监测系统拾震器的布置原则,通过现场校检,微震监测系统水平方向定位误差由优化前的37.5 m降到5.7 m,垂直方向定位误差由33.4 m降低到3.0 m,一定程度上解决了微震波传播异常现象。Abstract: In order to rationally explain the spreading route of the micro-seismic initial arrival waves in the strata and to improve the monitoring and measuring accu racy of the micro-seismic monitoring and measuring system, from the abnormal phenomena of the site micro-seismic spreading, with the basis theory of the seismic wa ve, a model was established individually with the spreading way and route of the seismic initial wave in a single rock stratum and the interface of the passed rock strata. The analysis on the spreading route of the micro-seismic initial arrival wave when the seismic sources and the seismic collector in a same rock stratum or not in a same stratum as the initial wave passing the interface of the rock strata.Based on the circumstances, the seismic collector layout principle of the micro-seismic monitoring an d measuring system was optimized.With the site correction, the horizontal directional position error of the micro-seismic monitoring and measuring system could be red uced from 37.5 m before optimized to 5.7 m and the vertical directional position error could be reduced from 33.4 m to 3.0 m.thus the abnormal phenomena of the micro -seismic spreading was solved in certain degree.