Effective Stress in Unsaturated Soils

[corechang]

Dear CODE_BRIGHT Team,

I simulated an unsaturated clay seal confined by the host rock (H-M).
As part of boundary conditions, the clay seal had suction applied and pore air pressure was constant and zero.
The results showed that the suction was dissipated after 20 years. I believe that in a confined space, the effective stress of the clay seal is the same as swelling pressure as hydration process is going on. This means that swelling pressure will be generated after 20 years after suction is gone. However, when I plotted the effective stress of the clay seal to see swelling pressure evolution, I saw swelling pressures generated at the beginning stages before 20 years.
Could anyone help me understand evolution of the swelling pressure at the beginning stages when the suction was applied?

Thank you very much for your help.

James

[code_bright]

Hi James,

I'm not sure I understood your problem.

A clay normally swells as it gets wet, so during the hydration process the suction will decrease meanwhile the swelling pressure will increase.

Regards,

Alfonso