地震层析成像的理论研究及其在岩溶发育区的应用

基于均匀介质中的波射线传播理论,应用直射线追踪方法进行射线走时正演计算,建立了速度模型。对模型分别进行SIRT算法和LSQR算法反演,对比分析后发现,LSQR算法在精度、效率和稳定性三个方面都能达到较好的平衡。以溶洞发育区某水电站右岸部分平硐勘探为实例,利用地震层析成像法准确探明了岩体速度分布情况和区内K25溶洞的空间分布位置,通过与其它方法结果的对比验证,表明地震层析成像法对于溶洞发育区具有分辨率高、图像直观、易于解释等优点。

Theoretical Study of Seismic Tomography and Its Application in the Karst Development Area

Based on the wave ray propagation theory in the homogeneous medium, a velocity model was developed for the forward calculation of ray using the straight ray tracking method. The model was simulated inversely using the SIRT and LSQR algorithms. The results showed that LSQR algorithm can achieve a better balance in the accuracy, efficiency, and stability. The seismic tomography method was applied to the adit exploration on the right bank of a hydropower station in the karst development area. This method can determine the velocity distribution of the rock mass and the spatial distribution of K25 cave in the area. Compared with the results obtained from other methods, it suggested that the seismic tomography method has the advantages of high resolution, intuitive image, and easy to explain when used for the karst development area.