Analysis and prediction of land subsidence along significant linear engineering

摘要

Land subsidence along significant linear engineering is mainly affected by long-term over-extraction of groundwater, mining of mineral resources, and karst collapse. In this paper, combined with the engineering geological and hydrogeological conditions, a three-dimensional fluid-solid model of land subsidence is established based on groundwater seepage and Biot's consolidation theories, in order to analyze and forecast the evolution law of the groundwater and land subsidence. The numerical results are verified using field monitoring data (InSAR and high-precision level measurement results). On the basis of monitoring and numerical results, the induced factors and distribution characteristics of land subsidence along the high-speed railway line are determined. According to different groundwater exploitation schemes, the development and evolution laws of ground subsidence in the future are predicted to analyze the influence of ground subsidence on high-speed railway line. The results suggest that (1) the main influencing factors of land subsidence in DK306 similar to DK313 and DK411 similar to DK414 sections are groundwater over-extraction, while DK276 similar to DK279 section is coal mining, DK368 similar to DK372 section requires a special research; (2) the decrease of land subsidence rate and differential subsidence are shown to be nonlinear with the reduction of groundwater withdrawal; (3) under the same mining conditions of groundwater, the land subsidence rate and differential subsidence are declining with time; (4) the surface differential subsidence is obviously sensitive to groundwater exploitation.