Deep Underground Science and Engineering (DUSE) is pleased to release this issue with feature articles reporting the advancement in several research topics related to deep underground. This issue contains one perspective article, two review articles, six research articles, and one case study article. These articles focus on underground energy storage, multiscale modeling for correlation between micro-scale damage and macro-scale structural degradation, mineralization and formation of gold mine, interface and fracture seepage, experimental study on tunnel–sand–pile interaction, and high water-content materials for deep underground space backfilling, analytical solutions for the crack evolution direction in brittle rocks, and a case study on the squeezing-induced failure in a water drainage tunnel and the rehabilitation measures.
The perspective article deals with the construction of the first underground energy storage complex in Xuzhou, China. This article entitled “Compressed air and hydrogen storage experimental facilities for sustainable energy storage technologies at Yunlong Lake Laboratory (CAPABLE)” (DOI: 10.1002/dug2.70043) reported the construction progress and technical development of lined rock caverns (LRC) facility for compressed air and hydrogen storage. This facility will focus on the verification of load transfer, damage and failure mechanism of the LRC structure, and the development of new materials for both lining and sealing layers. Three key problems for compressed air and hydrogen storage in underground spaces will be addressed: cavern stability, sealing efficiency, and minimum environmental impacts.
One review article focuses on the genesis and preservation mechanisms of 10 000-m ultradeep dolomite reservoirs in China (entitled “Genesis and reservoir preservation mechanism of 10 000-m ultradeep dolomite in Chinese craton basin”, DOI: 10.1002/dug2.12112). This is indeed the first article on ultradeep reservoirs published in the Journal of DUSE. Ultradeep dolomite reservoirs are particularly important for the future oil and gas explorations in China's marine craton basin. This review article systematically expounds the genetic mechanism and reservoir formation mechanism of ancient dolomite, clarified the limiting factors of dolomitization process and the preservation mechanism of dolomite reservoirs in deep buried environment, explored the spatial distribution of dolomite reservoirs, and identified the major zones of oil and gas exploration in 10 000-m deep layers. This article has no doubt provided the latest update on the fundamental knowledge for future oil and gas explorations in China.
The other review article reports on the multiscale simulations for mechanical problems of rocks (entitled “A review of multiscale numerical modeling of rock mechanics and rock engineering”, DOI: 10.1002/dug2.12127). This article systemically reviews both geometrical and mechanical multiscale behaviors of rocks in spatial and temporal scales. It summarizes the development of theoretical and numerical techniques in the characterization of multiscale behaviors, underlines the benefits, drawbacks, and application scopes of these characterization techniques on rock multiscale properties. This article also discusses the challenges on the quantitative relationship between microscopic damage of rocks and overall rock structural degradation in macroscale and points out the directions for future research.
This issue also contains seven articles on the mineralization of gold and adjoint rare earth elements (one article), laboratory tests on the mechanical and hydraulic properties of different materials and structures (four articles), analytical solution for crack growth direction (one article), and a case study on tunnel squeezing-induced failure (one article).
The mineralization of gold and adjoint rare earth elements were explored through geochemical analysis for the Kumasi Basin in Ghana (entitled “Petrogenetic and geochemical characteristics of some auriferous granitoids in the Kumasi Basin, Ghana: Implications for geodynamic settings and controls of orogenic gold mineralization in the Edikan Gold Mine”, DOI: 10.1002/dug2.12128). This study not only illustrates the formation of gold minerals through geochemical analysis but also discusses the formation of adjoint rare earth elements such as light rare earth elements, middle rare earth elements, and heavy rare earth elements. The research outcomes show that the mineralization of gold in the study area is structurally and lithologically controlled with shear zones, faulting, and veining as the principal structures controlling the mineralization. The method of analysis and results can provide a good reference for the exploration of minerals.
Rock failure is typically a progressive process and evolves with loading and environmental parameters. Two articles studied the failure mode of different materials. One is on the analytical solution of crack growth direction under shear stress. In this article (entitled “An analytical solution of direction evolution of crack growth during progressive failure in brittle rocks”, DOI: 10.1002/dug2.12117), a novel analytical method is proposed to evaluate the effects of shear stress and initial crack angle on the progressive compressive failure and microcrack growth direction in brittle rocks. The other article concerns a case study on tunnel failure having a low ratio of surrounding rock strength to overburden pressure (entitled “Analysis of squeezing-induced failure in a water tunnel and measure of rehabilitation: A case study of Tishreen tunnel, Syria”, DOI: 10.1002/dug2.12120). Through a case study, this article proposes a methodology to evaluate squeezing potential and failure mechanisms and develops a remediation measure for the tunnel service recovery through a proper support system of rock mass. This article highlights potential useful knowledge for the analysis of related tunneling problems in rocks.
Experimental investigations play vital roles in deep underground science and engineering. The migration of gas at the interface of two materials was investigated experimentally (entitled “Gas migration at the granite–bentonite interface under semirigid boundary conditions in the context of high-level radioactive waste disposal”, DOI: 10.1002/dug2.12118). A quantitative assessment was conducted to examine the effects of the interface between clay and host rock on gas transport in underground high-level radioactive waste (HLRW) disposal. The experimental results highlight the potential existence of preferential gas migration channels between the rock and bentonite buffer. This requires special consideration in the safety assessment of HLRW disposal. The flow in fractured porous media was simulated through micro-channel flows in the CT image-based pore network reconstruction model (entitled “In situ loading of a pore network model for quantitative characterization and visualization of gas seepage in coal rocks”, DOI: 10.1002/dug2.12114). The microscopic evolution of a reconstructed coal specimen pore fracture and the coalbed methane seepage law were assessed under dynamic loading. Both pores and fractures in coal have good fractal characteristics and an equivalent pore network model can be constructed, and the number of seepage channels in the model can be reflected by the magnitude of coordination number. The feasibility of the pore network model algorithm and COMSOL docking technology was also examined.
The tunnel-soil-pile interaction is an issue particularly in shallow underground works and the quick backfilling of mining space is critical to the safety of mining process. A shake table test was conducted on a prepared concrete tunnel–sand–pile interaction model for dry conditions (entitled “Seismic performance of concrete tunnel–sand–pile interaction by the shake table test”, DOI: 10.1002/dug2.12123). Both static load and seismic excitations were simulated. The displacement and moments of the tunnel were calculated and the relative density corresponding minimum displacements and moments were predicted. High-water material as a quick backfilling is widely used in underground spaces as a cost-effective and environmentally friendly backfill material with its superior water-to-solid ratio and quick setting time. The article (entitled: “Tri-axial compressive behavior of high-water material for deep underground spaces”, DOI: 10.1002/dug2.70040) investigated the effects of water-to-solid ratio, curing time, and lateral confinement pressure on the strength and bleeding mechanisms through triaxial compression experiments. Experimental results show that confining pressure has strong effects on the failure mode. The unconfined high-water material featured shear cracks, but no cracks were observed under confining pressure. The volume of these confined high-water materials under compaction exhibited continuous shrinkage associated with water bleeding. The mass of bleeding water increased with lateral confinement.
The breadth of research topics presented in this issue underscores the increasing scientific and practical focuses on different topics in deep underground. As discussed in the editorial at the 2-year growth of DUSE (entitled “Two-year growth of Deep Underground Science and Engineering: A perspective”, DOI: 10.1002/dug2.12139), research on Deep Underground Science and Engineering is compiling. Indeed, these cutting-edge studies provide the direction for the advancement in deep underground. The Editors wish to broaden its coverage in deep underground science and engineering. We are expecting that these publications can stimulate further innovation in deep underground science and engineering and builds better knowledge maps in deep underground. DUSE obtained its first impact factor of 5.0 in June 2025 and is now in the rank of JCR Q1. In addition, DUSE has been indexed by many well-established databases such as CSCD (2025.08), ESCI (2024.06), EI (2024.03), and Scopus (2023.07). The Editors cordially invite researchers and industry professionals to continue advancing this critical discourse through high-quality contributions, ultimately promoting safer and more sustainable deep underground practices worldwide.
