(1. 中國(guó)礦業(yè)大學(xué) 資源與地球科學(xué)學(xué)院,徐州 221116;2. 河南省地礦局第二地質(zhì)勘查院,鄭州 450000)
摘 要: 以麥克斯韋方程組為基礎(chǔ),推導(dǎo)出平面電磁波的波動(dòng)方程。電磁波在煤層中傳播時(shí),相位隨著電磁波的傳播產(chǎn)生一定的滯后。當(dāng)異常體和煤層的相位系數(shù)不同時(shí),坑道無(wú)線電波透視發(fā)射點(diǎn)和接收點(diǎn)之間的相位差發(fā)生變化,相位差成為異常體相位參數(shù)層析成像的基礎(chǔ)。利用時(shí)域有限差分算法對(duì)含有陷落柱、火成巖侵入?yún)^(qū)的兩種地電模型進(jìn)行正演模擬。結(jié)果表明:工作面內(nèi)的異常體改變了發(fā)射點(diǎn)和接收點(diǎn)之間的相位差,相位差的大小隨著異常體的規(guī)模、電阻率和介電常數(shù)的不同而不同。用代數(shù)重建法分別對(duì)陷落柱和火成巖侵入?yún)^(qū)進(jìn)行相位系數(shù)反演,兩種異常體的位置與模型中的實(shí)際位置相符。異常體的電磁參數(shù)不同,反演的相位系數(shù)值也不相同。相位系數(shù)層析成像可以用來(lái)反演工作面內(nèi)的地質(zhì)異常體。
關(guān)鍵字: 無(wú)線電波透視;相位系數(shù);層析成像;地質(zhì)異常體;電阻率;介電常數(shù)
(1. School of Resource and Earth Science, China University of Mining & Technology,
Xuzhou 221116, China;
2. The Second Geological Exploration Institute of Henan Bureau of Geology, Zhengzhou 450000, China)
Abstract:Based on Maxwell''''s equations, the wave equation of plane electromagnetic wave was derived. Phase produces a certain lag when electromagnetic waves propagate in coal seam. Phase difference of tunnel radio waves perspective between transmitting and receiving point changes when the phase coefficients of anomalous body and coal seam are different, and it becomes the foundation of phase parameter tomography of anomalies. FDTD algorithm was calculated for two geoelectric model forward modeling containing collapse column and igneous intrusions. The results show that the anomalous body in coal seam changes the phase difference between the launch point and the receiving point and the effect of phase difference varies with abnormal body size, resistivity and dielectric constant. The inversion of phase coefficient of collapse column and igneous intrusions was calculated using algebraic reconstruction technique and the geological abnormal body position matches the actual location of the model. The phase coefficients ??are different because the electromagnetic parameters of the abnormal are different. The phase coefficient tomography can be used to inverse the geological anomaly within the face body.
Key words: radio waves perspective; phase coefficient; tomography; geological anomaly; resistivity; dielectric constant


