Coupled seepage-elastoplastic-damage analysis of saturated porous media and its application to water conveyance tunnel

• We model the coupling of seepage-elastoplasticity-damage mechanisms of tunnel surrounding rock.
• Two energy-based damage potential functions are adopted to define damage evolution.
• We use two volumetric strain dependent parameters for permeability and porosities evolution.
• Two coupled stress-seepage constitutive equations are derived.
• The above constitutive model is validated by the in-place testing data.

Based on the plasticity, damage and seepage theory of equivalent continuum media, a fully coupled seepage-elastoplasticity-damage model for saturated porous media is proposed, which could reproduce the evolution of tensile and compressive damage, plasticity, porosity, permeability, and observed spatial distribution of pore pressure of the surrounding rock. This presented method is validated by the in-place testing data of the water conveyance tunnel project under the Yellow River, which is part of the South–North Water Diversion Project in China, and can be used as a reference for safety monitoring of similar hydraulic tunnel.