A Coupled Mixed Finite Element Biot Model for Land Subsidence Prediction in the Beijing Area

A coupled Biot model based on a three-field formulation, namely displacement-pressure-velocity, is set-up and used for the prediction of land subsidence in the Chaobai River alluvial fan, China, north-east of Beijing. The area has a regional size and has been recently characterized by a detailed statistical distribution of hydrofacies. The resulting model totals about 5 million unknowns with strong heterogeneities in the hydraulic and geomechanical properties distribution. The proposed numerical formulation allows for an efficient and accurate solution for a sample discharge from an existing well field, thus proving a robust computational tool for the forecast and management of the land subsidence risk in the area.