Experimental Study On Seismic Wave Three-dimensional Transmission Tomography Technology Of Mine Workface

Seismic CT transmission tomography technology has a stronger ability in detecting fine geological anomalous bodies. With an important application value in fine geological anomaly detection of mine working face. But in working face with a certain relief during detection, conventional2D CT tomographic techniques often cannot pinpoint geologic abnormal body size, shape and spatial location. Using three dimensional tomographic techniques can improve the accuracy of detection to some extent. However, the observation system, data acquisition, data processing and interpretation application has certain particularity, and need further study in-depth. The thesis by means of three-dimensional seismic tomography, using physical model test research, concluded that good for image reconstruction of fracture tectonic belt, the collection, observation system and reconstruction method. Meanwhile, have a certain understanding of seismic3D transmission tomography technology.The thesis by builds a three-dimensional observation system, and use3D straight line transmission tracking technology for ray tracing. It gets the coal seam section of internal seismic velocity profile by meshing, primary wave when pick up and inversion imaging. Analyses and explains internal coal geological characteristics according to the different size of wave velocity. It can improve the resolution of seismic CT tomographic imaging and interpretation precision by using three dimensional transmission tomography technology.Based on physical model test, established the corresponding observation system. Taking physical model of the traditional2D observation method and the improved3D observation way, it gets physical model simulate seismic wave velocity distribution of coal seam working face. The velocity difference is more obvious, it can clearly recognizes geological characteristics of internal simulation coal seam. Test results show that comparison of two different observation system of test probe, it can effectively analyzes geological characteristics of internal simulation coal seam. To provide scientific guidance for the application of three-dimensional transmission chromatography about the seismic in mine face abnormal geological exploration. Through select a representative workface of huaibei mining area. Choose model test obtained favorable collection, observation system and reconstruction method for workface to conduct on-site detection and data processing. Contrasting three-dimensional reconstructed image and actual geological anomalies reveal data of rebuilding regional, determine feasibility that application of three-dimensional transmitted seismic wave CT technology to detect geological anomalies of coal seam.The thesis also points out the deficiency existing in the three-dimensional transmitted seismic CT technology and the direction of future research. Especially in using one double row receiving vertical observation system to represent the3D observation system has some limitations, only use wave velocity to reflect plastid structure characteristics, without in-depth study of boundary effect, did not give a direct transmission line tracing method of quantitative evaluation, should carry on the omni-directional three-dimensional observation system build in future seismic three-dimensional tomographic imaging study, improve utilization rate of other physical parameters of seismic, focus on combining quantitative calculation and qualitative judgment way to verify the accuracy of the ray tracing.