Fractures such as joints, faults, veins, and bedding planes are ubiquitous in crustal rocks. These naturally-occurring discontinuities often comprise complex networks and dominate the geomechanical and hydrological behaviour of subsurface rocks.

Fractured rocks may deform in response to high seepage pressure, resulting in failure of surrounding rock and water inrush in underground excavations. For example, recently, two large water inrush disasters occur in the Longtan tunnel program in China induced by the tunnel passing through a water-rich fractured rock zone. The heterogeneous stress distribution may lead to variable local normal/shear stresses loaded on different fractures having distinct sizes and orientations and produce various fracture responses such as opening, closing, and sliding. Since the conductivity of fractures is critically dependent on the third power of fracture apertures, the geomechanical conditions can considerably affect the hydrological properties of fractured rocks including fluid pathways, bulk permeability, and mass transport. Hence studies on coupled mechanical and hydraulic properties of fracture networks will promote understanding of seepage failure mechanisms of fractured rocks under complex engineering conditions, such as tunnelling within aquifers, mining engineering, contaminant migration and nuclear waste isolation, geothermal energy extraction, and hydrocarbon exploitation.

This Special Issue aims to present recent advances in studies on coupled mechanical and hydraulic properties of fracture networks. We invite you to submit all relevant original articles and comprehensive reviews on theoretical developments, laboratory testing, field investigations, computational methods, and case studies.

Potential topics include but are not limited to the following:

• The construction of realistic discrete fracture networks that can represent the natural fracture systems
• Quantitative fractures evaluation based on fracture network reconstruction using 3D printing, micro-CT scanning, and scanning electron microscope (SEM) techniques
• Experimental studies on coupled hydro-mechanical process of fracture networks
• Novel numerical method of coupled hydro-mechanical in fracture network
• Novel prediction model of water inflow into underground excavations in subsurface fractures
• Water source prediction techniques and equipment of in subsurface fractures
• The stability and failure of fracture systems considering coupled hydro-mechanical process