Frequency domain full-waveform inversion in a fluid-saturated poroelastic medium

Summary Determining subsurface properties is of fundamental importance in exploration seismic imaging. Poroelasticity theory provides an opportunity to extract quantitative fluid- and attenuation-dependent properties from seismic data. Following Pratt’s frequency-domain full-waveform-inversion (FWI) procedure and extending the basic FWI equations from the elastic case to the poroelastic case, we implement poroelastic FWI (PFWI) of fluid-saturated porous media. By analyzing the sensitivity kernels of poroelastic parameters, we explain the reason why some parameters are more difficult to recover than others. We also show the analytical and numerical radiation patterns based on which we predict the trade-offs among parameters. In numerical experiments, we invert two models to demonstrate the feasibility and effectiveness of the proposed PFWI and to verify our predictions about trade-offs for two-parameter PFWI. Finally, we discuss the various factors that influence the inversion results.

Analysis of the Earth Surface Subsidence Caused By the Dewatering of Shenyang Subway in China

During excavation in deep foundation pit, the deformation of soil and earth surface caused by engineering dewatering is an important factor to affect engineering safety. In this paper, according to the data provided by the detailed survey report of route 1 subway in Shenyang, the subsidence laws of the ground and around buildings caused by the dewatering of route 1 subwaywere analyzed by using Coupling System of Flow & Solid in FLAC-3D which is based on poroelasticity theory and consolidation theory, and preliminary results were obtained.