One-dimensional consolidation of saturated degradable porous media with degradation-dependent compressibility

Abstract

For degradable porous media (DPM) experiencing solid particle or mass loss, the volume change process is complex. To investigate the pore water pressure response and associated deformation during the consolidation process of saturated DPM theoretically, the generalized governing equation for one-dimensional (1-D) consolidation of saturated DPM was proposed. Then, saturated municipal solid waste (MSW) was taken as an example. The generalized and simplified 1-D consolidation models were established for saturated MSW, respectively. Analytical solution to the simplified 1-D consolidation model considering degradation-dependent compressibility only was derived for saturated MSW. Based on this analytical solution, case studies were carried out. Excess pore water pressure (usw) being larger than the initial value was found in deeper waste during the early stage of consolidation under a constant surcharge load. This is because the loading effect resulted by the increase of compressibility is greater than the unloading effect resulted by the increase of void space. An increase of degradation rate coefficient c could result in greater loading effect, and hence causes increasing usw in waste. The numerical results are of wider interest, being applicable to other DPM.