Influence of coupling effect in the chemo-hydro-mechanical consolidation of saturated soil layer

In geological sites containing chemical pollutants, the clay buffer layer (CBL) is frequently utilized to isolate the pollutants from the external environment. Moreover, hydraulics, mechanics, and chemistry jointly pose impacts on the consolidation of CBL and the diffusion of chemical substances. In order to consider the coupled effect (termed chemo-hydro-mechanical-CHM), a one-dimensional consolidation model that fully considers CHM coupling (such as convection, ultrafiltration, and osmotic efficiency) is established. In the developed model, the excess pore pressure, chemical concentration, and soil settlement during the consolidation process are calculated via finite Fourier transform and inverse transform. Finally, the CHM coupling effect on consolidation under different conditions is analyzed and discussed. The results indicated that the coupling effect slowed down the entry of chemical substances into the soil layer so that the excess pore pressure dissipated faster, and the negative pore pressure was larger. Furthermore, the coupling effect increased the maximum settlement during consolidation but did not change the final settlement. The coupling effect prolonged the time of consolidation. In addition, the higher the osmotic efficiency, the greater the coupling effect, but the osmotic efficiency did not affect the time of consolidation.