Groundwater and stability in deep mining

Deep Underground Science and Engineering (DUSE) is pleased to present this special issue on Groundwater and Stability in Deep Mining. As mining operations progress to greater depths to meet the growing global demand for mineral resources and energy, the challenges associated with groundwater control and rock mass stability have grown increasingly critical. These challenges are exacerbated by complex geological conditions, structural heterogeneity, and intense mining-induced disturbances. This special issue seeks to address these challenges by showcasing cutting-edge research and technological advancements in the field.

This special issue features a collection of 12 articles (seven articles for this special theme and five articles for regular submission) exploring diverse aspects of groundwater and rock stability in deep mining. The contributions span a broad range of topics, from experimental investigations of thermo-mechanical properties of cement grouts to comprehensive reviews of shear behaviors in bolted rock joints under varying stress conditions, along with field-based studies on grout propagation in engineering applications. One article (Title: Field investigation of grout propagation within a caving mass under flowing water condition in a metal mine, DOI:10.1002/dug2.70001) is particularly noteworthy, examining the complex dynamics of grout propagation within a metal mine's caving mass under active water flow conditions. This study provides critical insights for mitigating water–sand mixture inrush hazards and advancing mining safety practices. Another article (Title: A comprehensive review of experimental studies on shear behavior of bolted rock joints with varying rock joint and bolt parameters and normal stress, DOI:10.1002/dug2.12091) presents a systematic review of experimental investigations into shear behaviors of bolted rock joints, emphasizing the effects of joint roughness coefficient (JRC) and normal stress on shear strength. Further study analyzes permeability coefficient variations in soil-rock mixtures within fault zones under varying stress states, establishing quantitative relationships between permeability coefficients and stress conditions (Title: Study on the variation of the permeability coefficient of soil-rock mixtures in fault zones under different stress states, DOI:10.1002/dug2.12100).

This special issue further encompasses several critical investigations, including: (1) the thermal degradation effects on cement grout properties in deep rock grouting applications under elevated ground temperatures (Title: Effects of elevated ground temperatures on properties of cement grouts for deep rock grouting, DOI:10.1002/dug2.12073); (2) the characteristic evolution of in situ stress fields and associated rock mechanical property alterations in deep mining environments (Title: A comprehensive study on in situ stress field characteristics and changes in rock mechanical properties in deep mines in northeastern Yunnan, China, DOI:10.1002/dug2.12124); (3) the implementation of distributed fiber-optic sensing technology for enhanced geological condition transparency in coal mining operations (Title: Research on transparency of coal mine geological conditions based on distributed fiber-optic sensing technology, DOI:10.1002/dug2.12134).

This special issue include six articles on innovative studies in different directions: (1) digital 3D reconstruction techniques for microstructural characterization of blast-induced rock fracture surfaces (Title: Digital reconstruction of three-dimensional contours and its application to microstructural evaluation of postblast rock fissure surfaces, DOI:10.1002/dug2.12111); (2) the numerical models of flawed granite under dynamic loading are constructed through an integration of digital image processing (DIP) techniques with the discrete element method. These constructed models can closely resemble actual rock images (Title: Fracturing behaviors of flawed granite induced by dynamic loadings: A study based on DIP and PFC, DOI:10.1002/dug2.12088); (3) damage progression in sandstone formations subjected to cyclic injection-withdrawal loading during underground natural gas storage operations in repurposed mines (Title: Damage evolution of surrounding sandstone rock under charging-discharging cyclic loading in the natural gas storage of abandoned mines based on the discrete element method, DOI:10.1002/dug2.12099); (4) coupled thermal-hydro-mechanical effects on grout penetration behaviors in individual fractures under dynamic groundwater flow conditions in deep mining environments (Title: The effect of thermal-hydro-mechanical coupling on grouting in a single fracture under coal mine flowing water conditions, DOI:10.1002/dug2.12144); (5) damage evolution characteristics and acoustic emission patterns in sandstones under cyclic loading in deep mines and fracture propagation behaviors in flawed granite subjected to dynamic loads (Title: Experimental study on the damage characteristics of cyclic disturbance and acoustic emission characteristics of different types of sandstones under high stress in deep mines, DOI:10.1002/dug2.12093); (6) a case study on the stability assessments of large-scale underground caverns intersected by interlayer shear zones (Title: A case study on the stability of a big underground powerhouse cavern cut by an interlayer shear zone in the China Baihetan hydropower plant, DOI:10.1002/dug2.12094). This article reported a 9-year study on the deformation and stability problem of a large deep underground cavern. It provides a full chain in underground cavern stability analysis: Parameter determination through site investigations and laboratory tests, numerical simulation on the stability of heterogeneous rock masses, site monitoring and numerical model verification, creative replacement tunnels for cavern stability control and site assessment. All of these articles offer multidisciplinary perspectives and cutting-edge insights into the field.

DUSE highly appreciated the efforts of the Guest Editors for the success of this special issue. The Guest Editors are Prof. Wanghua Sui (China University of Mining and Technology), Prof. Xiaocong Yang (BGRIMM Technology Group), Academician Prof. Ravi Jain (University of the Pacific, California, USA), Prof. Dmytro Rudakov (Dnipro University of Technology, Ukraine), Prof. Yajun Sun (China University of Mining and Technology), Prof. Bin Zhang (China University of Geosciences, Beijing), and Prof. Wenhui Tan (University of Science and Technology Beijing).

The breadth of research presented in this special issue underscores the increasing scientific and practical focus on groundwater and rock stability challenges in deep mining. By compiling these cutting-edge studies, DUSE aims to stimulate further innovation in the field. We cordially invite researchers and industry professionals to continue advancing this critical discourse through high-quality contributions, ultimately promoting safer and more sustainable deep mining practices globally.