| Abstrakt: |
Abstract: Faults pose a great threat to the safety of tunnel and roadway construction. Expanding the scientific community’s understanding of advanced fault detection through research is therefore of critical importance. However, narrow road way space often restricts sources and receivers positioning, resulting in small migration aperture problems during advanced migration imaging. The resulting artifacts make it impossible to analyze occurrence parameters of faults, such as dip and trend. In this paper, we introduce a solution to this problem with three-component (hereafter called "3C") reflected signals. The solution can be roughly divided into three steps. First, we use a covariance matrix to calculate the principal polar ization direction, which indicates the principal energy propagating direction of reflected waves. A factor is intr oduced to represent the principal polarization direction. Second, we establish a weighted function of the factor and apply the function in migration computation. Finally, we put forward a polarization migration imaging technique to eliminate the artifact so that we can accurately predict occurrence parameters. It has been proven that polarization migration is an efficient way to achieve advanced imaging of faults under small migration aperture condition through numerical simulations, water sink model experiments, and roadway field experiments. |
