Physics of Hydromechanical Instability in Geomaterials for Underground Construction

Underground construction projects—including tunnelling, deep excavations, mining operations, and large-scale caverns—are increasingly being developed in complex geological environments where water and mechanical stress interact through coupled physical processes. The presence of groundwater significantly alters the behavior of geomaterials, leading to reduced strength, time-dependent deformation, and eventual failure. Catastrophic events such as water inrush, surrounding rock collapse, and rainfall-induced slope instability are frequently triggered by hydro-mechanical coupling. Understanding the physical mechanisms that govern these processes is essential for safe and sustainable underground construction. However, the fundamental physics of hydro-mechanical instability remains insufficiently understood, particularly under coupled stress-seepage conditions.

The goal of this Research Topic is to advance the fundamental understanding and predictive capabilities of hydro-mechanical instability phenomena in geomaterials relevant to underground construction. We seek to bring together researchers and engineers working at the intersection of rock mechanics, soil mechanics, poromechanics, hydrogeology, and engineering physics to address key challenges in this field.

Specific objectives include:
• elucidating the physical mechanisms of water-induced softening, fracturing, and time-dependent deformation in various geomaterials
• developing improved analytical, numerical, and experimental methods for characterizing coupled hydro-mechanical behavior
• establishing criteria for stability assessment and failure prediction of underground openings under hydraulic loading
• translating fundamental research into practical guidelines for risk mitigation in underground construction projects.

By achieving these goals, this collection aims to bridge the gap between theoretical physics and engineering practice, ultimately contributing to safer design and operation of underground infrastructure worldwide.

This Research Topic welcomes contributions addressing the physics of hydro-mechanical instability in geomaterials for underground construction. Themes of interest include but are not limited to:
o Coupled hydro-mechanical for saturated/unsaturated geomaterials
o Water-induced softening, fracturing, and time-dependent deformation
o Multi-scale experimental studies on permeability and failure evolution
o Analytical and numerical methods for stability assessment
o Case studies on instabilities in tunnelling, mining, and slope engineering

We invite Original Research, Review, Methods, and Mini Review articles. All contributions must advance the physical understanding of hydro-mechanical instability and demonstrate clear relevance to underground construction applications.