Coupled Flow and Deformation Analysis in a Multilayered Poroelastic Half-Space due to Fluid Extraction and Injection

This study presents an analytical solution for calculating the time-dependent subsidence and pore fluid pressure generated by fluid extraction in a layered half-space. The solution considers various source types, including point and circular sources, and employs Hankel and Laplace transforms to address the problem in the radial and time directions, respectively. A rigorous numerical solution using the multidomain and incremental differential quadrature method (IDQM) is also provided. The accuracy of both methods is validated through four case studies demonstrating excellent agreement between the proposed analytical and numerical solutions and those found in the literature. The study reveals that point sources induce higher dimensionless pore pressure and settlement. Furthermore, the accuracy of the IDQM is shown to be more sensitive to vertical discretization than to radial discretization. Additionally, the effects of various material parameters and source types on displacements and fluid pressure are thoroughly investigated.