This study aims at answering an important question: Is the joint roughness coefficient (JRC) a suitable parameter for quantifying the hydro-mechanical behavior of smooth to slightly rough rock joints? To answer this question, we used 3D printing technology to produce matched and mismatched joints with the same surface configuration (profile) and joints with identical JRC values but different surface

The shear behavior of infilled rock joints remains challenging to predict due to complex interactions between joint roughness coefficient (JRC) and infilling ratio. This study examines how joint roughness (JRC 2.8–16.76), infilling ratios (0–2), and normal stresses (0.5–8 MPa) affect shear behavior. Specimens were sheared at 0.6 mm/min while monitoring acoustic emissions to track strength changes and

Fractures in the host rock surrounding a high-level radioactive waste (HLW) repository can act as primary conduits for groundwater flow and radionuclide migration, significantly impacting the repository's safety and long-term stability. Therefore, precisely characterizing the hydrological properties of these fractures is essential. This case study investigates fracture hydrology at the Beishan Exploration

To analyze the fault slip mechanism under static and cyclic disturbance loads during construction, a series of true triaxial monotonic and cyclic loading tests on rough fractured granite were conducted. The effects of confining pressure and loading path on the slip characteristics of fractured granite with a 60° fracture angle were explored. Based on stress, strain monitoring, and acoustic emission

In geothermal engineering, dynamic loads (e.g., drilling, hydraulic fracturing) and thermal shock between working fluids and high-temperature reservoirs significantly affect well-wall stability and exploitation efficiency. This study performed a series of dynamic tensile experiments on granite flattened Brazilian disc (FBD) specimens treated by cyclic thermal shock (CTS) using a split Hopkinson press

Layered rock slopes naturally formed or excavated are prone to buckling failure. Current assessment methods predominantly rely on flexural buckling theory (i.e., elastic instability), but in fact this type of destabilization rarely occurs. Thus, an applicable stability evaluation method is urgently needed. Based on the upper bound theorem, this study develops a three-hinge buckling (THB) kinematic

Hydraulic fracturing (HF) is a widely employed technique for determining in situ stress. A critical aspect of this technique is the interpretation of the shut-in pressure to ascertain the magnitude of the minimum principal stress. Existing interpretation methods primarily focus on the pressure decay rate or its simple transformation, and an effective physical model has not yet been established to quantitatively

The crack initiation stress threshold (σci/σp) is an important parameter in the process of brittle failure of rocks, and it plays a significant role in assessing the macroscopic deformation and micro-fracture characteristics of rocks. In this study, the rock system during loading stage is equivalently modeled as a viscoelastic system undergoing light damping vibration, and the bifurcation characteristics

Coalbed methane (CBM) is a clean energy source that requires understanding of coal pore structures and flow behavior for efficient development. In deep formations with high gas content and low permeability, variations within coal pore structure influence methane extraction efficiency. This study explores the dynamic regulatory mechanisms influencing flow anisotropy in coal pore structures across varying

Cemented granular materials (CGMs) such as sedimentary rocks, ceramics, and sandstones are central to both natural geologic systems and engineered structures. Despite their importance, the relationship between microscopic and macroscale mechanical behavior in natural CGMs is not yet fully understood. To help bridge this gap, synthetic analogs like sintered soda-lime glass beads offer a platform for

Cracks have been proven to significantly impact soil slope stability, whereas their mechanisms influencing rock slope stability have not been effectively investigated. Within the upper-bound theorem framework, the non-linear Hoek-Brown yield envelope is divided into multiple segments using a series of tangent lines to establish a three-dimensional (3D) multi-segment failure mechanism and a discontinuity

Laser processing is an effective method for cutting extraterrestrial rocks, making it potentially useful for space mining. By comparing laser processing of terrestrial basalt and the Hammadah al Hamra 346 (HaH 346) chondrite meteorite, we investigated the influence of iron-nickel (Fe-Ni) metals on laser-induced melting, cavity formation, and recrystallization. Experimental results revealed that the

For underground mines in the vicinity of coastal regions, using the mine water to prepare cemented tailings backfill (CTB) is an ideal synergistic treatment of the solid waste (tailings) and liquid waste (saline water). High concentrations of ions in mine water such as Cl−, Na+, Ca2+, Mg2+, may affect the hydration process of binders and thus alter the shear behavior of CTB. In this study, shear tests

Transversely isotropic rocks (TIRs) are widespread in geological formations, and understanding their mechanical behavior is crucial for geotechnical and geoengineering applications. This study presents the development of a novel analog material that reproduces the directional mechanical properties of TIRs. The material is composed of quartz sand, mica flakes, and gelatin in adjustable proportions,

To investigate the degradation of "grout-rock" interfaces caused by freeze-thaw (F-T) cycles in fractured rock bodies following grouting in cold regions, this study systematically examines the shear stress characteristics and F-T resistance of ordinary cement grout (OC), graphene oxide-modified grout (OC-I), and microsilica-modified grout (OC-II) under saturated conditions. Utilizing scanning electron

A water dry-wet (DW) cycle, triggered by water injection into coal seam, affects the pore-fracture structure (PFS) of the coal, thus changing the storage environment of coalbed methane (CBM). In order to study the effect of DW cycle on the PFS, a nuclear magnetic resonance technology (NMR) is employed to measure the PFS after different DW cycles by carrying out online loading experiments with mechanical

Forecasting violent rockbursts remains a formidable challenge due to significant uncertainties involved. One major uncertainty arises from the intermittency of rock failure processes, typically characterised by a series of progressively shorter quiescent phases punctuated by sudden accelerations, rather than a smooth continuous progression towards the final breakdown. This non-monotonic evolution of

High extraction columns are one of the newest trends emerging in block cave mining. These columns present significant benefits in terms of preparation costs. However, they are also associated with significant challenges such as high stresses, the presence of fine material, risk of dilution, and the need to modify conventional mining designs. Given these challenges, understanding the behavior of the

Fragmentation serves as a critical blasting quality indicator in hydropower engineering, directly influencing rock extraction efficiency, operational quality, and economic costs. This study introduces a simulation method based on finite element digital sieving to address the limitations of traditional finite element methods (FEM) in predicting fragmentation. The method integrates finite element results

Microseismic monitoring is widely used to detect instability hazards. Specifically, the quick and effective identification of microseismic events, such as noise, explosions, and drilling activities, is critical for determining mine stability and safety. This study employed features including the mean and standard deviation of frequencies extracted by short-time Fourier transform (STFT), short-term

Conventional rock mechanics testing faces significant limitations, including destructive testing conditions, time-intensive procedures, the inability to directly observe internal plastic zone expansion, and limited generalization capability. To overcome these challenges, this study uses granite with varying weathering grades as a case study, establishing a connection between uniaxial compressive strength

During deep coal mining, the coal mass inevitably suffers damage under three-dimensional stress due to dynamic loads. This damage renders the coal highly susceptible to instability and failure under static loads, thereby posing a threat to engineering safety. Therefore, it is crucial to investigate coal affected by true triaxial dynamic damage. This study aims to elucidate the mechanical properties

The peril posed by time-delayed rockburst significantly undermines the safety of deep-buried tunnel construction and operation, with dynamic disturbance recognized as a pivotal triggering factor. Vibration monitoring of critical Tunnel Boring Machine (TBM) components and surrounding rock surfaces within TBM-constructed tunnels shows that low-frequency dynamic disturbance affects the failure behavior

The development and utilization of deep earth resources have become a strategic scientific and technological issue that humanity must address. Shafts serve as the vital passage to the deep earth, and full-face shaft boring machines (SBMs) are crucial for mechanized shaft construction. In this study, the inefficiency of rock-breaking with disc cutters was investigated by analyzing the SBM's unique conical

The complex tectonic history of the Mae Moh mine in Thailand created normal faults, which formed a relay ramp that controlled the failure mechanism of the massive block in the C1-west wall. Geotechnical monitoring data between 2021 and 2023 revealed that the slope deformation was predominantly influenced by mining activities and precipitations, resulting from the hydromechanical (HM) coupling process

The application of acoustic emission (AE) techniques can capture the formation of discontinuities during crack propagation. Although the received waveforms exhibit significantly different frequency spectrum, the high and low frequency components are usually not separately examined and processed. In addition, the radiation efficiency and acoustic efficiency in acoustic radiation are not well analysed

The dynamic fracture of quasi-brittle materials, including rocks and concrete, is characterised by highly inhomogeneous deformation along localised cracking paths, exhibiting a significant rate-dependent effect that governs both fracture toughness and crack propagation trajectories. To capture the significant discontinuities of the localised fracturing band and its rate-dependent failure mechanisms

Rock spalling is a brittle failure process that occurs around tunnels excavated in hard rock under high in-situ stress states. In nuclear waste disposal, spalling in fractured crystalline rock could create connected fractures, potentially providing pathways for radionuclides. Robust numerical models are therefore needed to evaluate the extent of rock spalling so that the design and layout of a prospective

Shale oil and gas—important unconventional hydrocarbon resources—exhibit huge exploration potential. The tensile mechanical properties of shale are crucial for enhancing oil and gas recovery. Herein, molecular dynamics simulations were performed to investigate shale tensile properties. The influence of the mineral composition and pore structure of shale on its tensile mechanical properties and underlying

High voltage electric pulse (HVEP) technology is expected to revolutionize deep resource extraction and underground space engineering construction technology. Understanding the establishment mechanism of the plasma channel and the pulsed discharge impact on the mechanical characteristics of rock is considered key to the widespread utilization of this technology. In this work, cycle discharge experiments

We develop a novel computational framework based on the particle finite element method for simulating rockburst phenomena, from pre-failure initiation to failure evolution and to post-failure mobilisation and ejection, across spatiotemporal scales in hard rocks. The proposed framework builds upon a rigorously validated and extensively calibrated particle finite element model, distinguished by its unique

In deep reservoirs, high pressure and horizontal stress difference lead to elevated breakdown pressure and reduced stimulation efficiency during multi-cluster hydraulic fracturing. To address these challenges, we carry out experimental studies to reveal the effects of fluid viscosity and flow rate, perforation cluster density, and flow control methods on the initiation and propagation of hydraulic

The shear resistance between contacting rock surfaces under normal confinement is governed by the asperities truly involved in shear, i.e., true-sheared asperities. However, the prediction of joint peak shear strength considering mechanical contributions of true-sheared asperities remains unresolved. Here, we developed a three-dimensional (3D) peak shear strength criterion by independently quantifying

Basic rocks are considered ideal materials for microwave breaking due to their high strength and high microwave sensitivity. However, the heating characteristics and weakening mechanisms of basic rocks under microwave irradiation have not been systematically investigated. In this study, the multimode microwave irradiation experiments were conducted on two types of diabase and three types of basalt

With the extensive application of numerical simulations in engineering fields such as mining, tunnelling, and petroleum, enhancing the accuracy of simulation tools to ensure their reliability has become a widely discussed issue. Using basic rock mechanics experiments to validate numerical models often encounters problems when these models are applied to more complex tests, resulting in distorted simulation

Accurate modeling of natural fracture networks is crucial for understanding subsurface structures and their properties, yet traditional methods often struggle with complex geometries and scale transitions. In this study, we present a novel non-parametric machine learning model, FracGen, utilizing the Single Image Generative Adversarial Network (SinGAN) to reconstruct and upscale natural fracture networks

By means of a novel experimental method for rock collision reported recently, a total of 27 cylindrical rock specimens from three rocks were tested. The collision process was filmed by a camera, the velocity of each specimen was measured by a laser instrument, the stress wave energy transferred to the transmitted bar was measured by the strain gauges, and all fragments of each specimen were collected

When tunnel boring machines (TBMs) excavate intact high-strength rock masses, creating kerfs on the tunnel face is a promising solution to enhance the efficiency of TBM cutters. The cutters can be arranged to cut between kerfs or cut along kerfs. The rock breaking mechanism of cutting along kerfs is not fully revealed yet, and a quantified comparison in cutting performance between the two arrangements

Rock-breaking is a fundamental process in subsea tunnel construction, particularly during deep trench excavation. Understanding the failure process and permeability evolution of rock masses under hydro-mechanical coupling is essential for optimizing excavation plans and ensuring construction safety. Due to the challenges of capturing crack propagation and permeability evolution solely through experiments

Natural gas hydrate (NGH) is a potential alternative source of energy for the future, and the low mining efficiency severely restricts its commercial utilization. Recently, the cavitation jet technology has been emerging as a prospective way of drilling rate improvement for the industrial development of NGH. The breaking and mining efficiency of cavitation jet is strongly associated with the nozzle

Fracture permeability is influenced by the mechanical properties of geomaterials, surface geometry, aperture distribution, and stress conditions. However, accurately characterizing fracture surfaces and aperture distributions, along with their effects on permeability under stress remains challenging. This study systematically investigates the evolution of fracture permeability and closure behavior

Precise prediction of crack opening displacement (COD) is necessary to control it within a certain threshold to ensure safety of critical buried rock structures (e.g. geological disposal facilities), and rock COD nowadays tends to be estimated using distributed fiber optic sensing (DFOS) data. The frequently used methods for computing COD of engineering structures from DFOS data are based on analytical

A series of laboratory experiments were conducted on Hawkesbury sandstone specimens that were exposed to a simulated fire following the modified hydrocarbon fire curve (MHC). For comparison, a similar test program was performed on specimens heated at four rates (2 °C/min, 5 °C/min, 10 °C/min, and 20 °C/min) up to 1100 °C and untreated specimens. Both uniaxial compressive strength (UCS) and elastic

Underground mining catastrophes mainly stem from the gradual weakening of coal and its adjacent rock formations, induced by complex stress variations occurring during loading and unloading processes. Although several cyclic loading and unloading tests have been conducted on rocks to evaluate this concern, there is a dearth of understanding of the distinct damage mechanisms that occur in coal and rocks

The discretization algorithm for the root mean square of the first derivative (RMSFD) significantly affects the effective characterization of rock joint profile roughness and the accurate evaluation of the joint roughness coefficient (JRC). The classic discretization algorithm Z2 fails to distinguish morphology roughness differences in isomeric profiles, limiting its characterization capability. To

Understanding the propagation behavior of cement grout in rough-walled fractures is crucial for predicting its effectiveness and design of optimal grouting schemes. To investigate radial propagation of cement grout in saturated rough-walled fractures, a water-cement grout two-phase flow model in rough-walled rock fractures is developed using the phase field method, Herschel-Bulkley model, and mass

The bond-based peridynamics shows significant potential in describing and simulating the continuous-discontinuous problems like rock mass. However, the theory developed so far with account of the bond stretch and shear mechanisms exhibits unreasonable prediction of bond force and the appearance of negative shear stiffness when Poisson’s ratio exceeds a critical value. In this work, the root cause behind

The intrinsic anisotropy of shales, arising from their complex microstructure, including mineral alignment and bedding orientation, significantly influences seismic wave propagation, impacting subsurface imaging and reservoir characterization. Despite extensive research on shale anisotropy, studies employing cubic specimens under true-triaxial conditions, which provide a more realistic simulation of

With the expansion of underground engineering into deeper levels, the frequency of rockburst disasters has gradually increased, posing serious threats to the safety of construction personnel and equipment. The occurrence of rockbursts typically involves information about time, location, and intensity, which makes it challenging for traditional single‒intelligence prediction methods to capture the multiple

Even though most past endeavors concluded no significant mechanical weakening of chalk flooded by supercritical CO2, here, we comprehensively assess the mechanical response of a depleted chalk reservoir by considering the most pessimistic experimental results reported in literature in terms of mechanical alteration of chalk by supercritical CO2. The primary aim stems from the lack of simulation studies

The grain size effect of rocks is crucial for engineering applications, including mining, tunneling, and oil extraction. Previous studies on the effect of grain size revealed discrepancies between experimental results and numerical simulations, hindering accurate predictions of rock strength and deformation. Initially, a parallel bond model was applied to describe the grain boundary contacts and investigate

The unpredictable development of random cracks in reinforced concrete linings under high internal water pressures poses significant challenges for the operational safety and management of hydraulic tunnels, particularly in water-permeable linings used in pumped storage power stations. To address this issue, this study introduces an innovative structural design: a reinforced concrete water-permeable

Early warning of rockburst is a critical part of deep rock engineering; yet the selection of reliable indicators, the establishment of effective warning thresholds, and understanding of triggering mechanisms require further refinement. This paper presents a novel framework for early warning of rockburst, developed based on the integrated monitoring of infrared (IR) and acoustic emission (AE) data.

Shield tunnelling was inspired by the burrowing process of bivalve mollusk shipworm. Recent studies have discovered new species of freshwater bivalves capable of burrowing into underwater rock. These bivalves dissolve cementing minerals using organic acid and then trap hard minerals on their shell surfaces via microbial biofilm to promote mechanical abrasion. This study aimed to understand the bioerosion

Seismic monitoring of underground longwall mines can provide valuable information for managing coal burst risks and understanding the ground response to extraction. However, the underground longwall mine environment poses major challenges for traditional in-mine microseismic sensors including the restricted use of electronics due to potentially explosive atmospheres, the need to frequently and quickly

Fatigue fracturing technology is of great significance to improve the efficiency of geothermal energy extraction and reduce the risk of induced earthquakes. In this study, granite with thermal storage potential was selected as the sample, and carried out conventional fracturing (monotonic pressurization) and fatigue fracturing (pulsating pressurization) tests. First, the influence of fracturing mode

Transverse thermal fractures in horizontal wells can be induced by cold fluid injection into high-temperature formations during drilling, geothermal production, CO2 storage, etc. As these fractures propagate, some are arrested due to stress interaction, resulting in a hierarchical fracture pattern. This study investigates the propagation and arrest of radial transverse thermal fractures in a horizontal

Tunneling in brittle rock masses under high stress may be accompanied by fracture-induced collapses, that is a complete loss of the structural load carrying capacity. Predicting the location and extent of the collapses is crucial for ensuring construction safety and designing support systems. This study proposes a novel fracture-mechanics-based continuum model for simulating excavation-induced collapses

The mechanical properties of frozen rock mass are primarily determined by that of ice and ice-rock interface, the latter is further controlled by the microstructure at ice-rock interface. To investigate the temperature-dependent variations in the microstructure at ice-rock interface, the concept of ice-rock interface cohesive zone (ICZ) was firstly defined. Ultrasonic and NMR (nuclear magnetic resonance)

The elastic energy released by the tensile fracturing of hard roof strata is partially transferred to surrounding rocks and causes rockbursts during underground coal exploitation. However, the effect of rock mineralogical properties on the transferred energy and rockbursts has not been quantitatively analysed. In this study, three-point bending tests were conducted to reproduce the tensile fracturing