A physical model test is carried out to simulate the blasting disturbance on the underground tunnel. The test including four blasting events with different blasting locations, where two blasting angles (\(\left| \alpha \right|\)) and two blasting distances (D) are designed. The surface deformation characteristics of the physical model are observed by a DIC system. The deformation responses of four

Large-scale panel destressing is a rockburst control technique that is used to create a stress shadow in the ore pillar to be mined. The technique aims to reduce the pillar burst proneness by deviating the major induced principal stresses away from the concerned zone of interest. The destress panels, situated in the pillar hanging wall, are choke-blasted with high explosive energy density, and the

To determine the influence of bedding planes on pure mode I and mixed-mode I–II dynamic fracture toughness (DFT) and crack propagation characteristics of coal, a modified split Hopkinson pressure bar (SHPB) system is used to test notched semi-circular bend (NSCB) specimens. The DFT is calculated by the finite element code Abaqus. Two strain gauges are used to measure the crack propagation velocity

Outburst energy is a major factor influencing coal and gas outbursts, albeit its estimation is difficult owing to the lack of amenable means for quantification of gas desorption. In the past decades, determining the mechanism of outbursts is one of the most challenging issues in rock mechanics. In this study, a triaxial coal and gas outburst simulation system was employed to perform simulated experiments

Quantitative stability evaluation of multi-tunnel structure is an important issue related to the safety assessment and stable construction of geotechnical underground tunnels. In this work, the overall failure process of twin tunnels were exhibited by a physical simulation based on the 3D printing (3DP) sandstone analogues model, and a safety factor method was also presented for evaluating the general

Coarse arches are a common issue in caving mines where large fragments are expected. These arches interrupt ore flow in drawpoints, decreasing available draw area, and also increasing the possibility of non-uniform draw, which can increase fine migration, mud-rush risk, and induced stress in the caved column. Moreover, hang-up removal is operationally complex and dangerous. The literature on gravity

A split three-characteristics method was proposed that can be used to analyze the stress wave propagation through a rock mass with double-scale discontinuities (micro-defect (MD) and macro-joint (MJ)). The mechanisms of the effects of MDs and MJs on stress wave propagation were investigated. The characteristic lines were divided into the three basic elements of triangle, diamond and separated diamond

Columnar jointed rock masses (CJRM), characterized by regular arrays of polygonal prisms or columns, are exposed in the dam foundation of the Baihetan hydropower station and pose a challenge to the stability of the project. To understand the hydro-mechanical behaviour of Baihetan CJRM, triaxial compression experiments are carried out on artificial CJRM specimens with regular arrays of hexagonal columns

The focus of this work is toward an investigation of the mechanical response of a variety of rocks to indentation loading as a close condition to drilling application. A rock classification method is introduced based on the mechanical response of the rock when loaded by a spherical indenter. Spherical shape is selected for the indenter as a common geometry, which to some extent represents most of the

The current study shows that heating a cased borehole in low-permeability shale rock can induce plastic deformation, leading to the closure of the casing annulus and decreasing annulus connectivity. The thermally induced borehole closure is interesting for the field operation of plug and abandonment (P&A), as it potentially saves operation cost and time by avoiding cutting casing and cementing. Lab

Coal is the major energy resource in China, but the recovery of coal is constantly under the threat of rock bursts, which has been impeding safe and highly efficient coal production for decades. A better understanding of the rock burst mechanism and its monitoring and management strategies is critical to improving coal extraction efficiency with an improved health and safety environment. In this paper

The changes in the composition and structure of the rock matrix caused by weathering lead to great alterations in its mechanical and physical properties. When considering this, geologists and engineers should pay special attention to materials from transition zones, namely, between the soil and rock over the weathering profiles. This research aimed to perform a wide characterization of the physical

Dimension and ornamental stones used for built heritage are frequently affected, under all climates, by intense weathering induced by the transport of saline solutions. Accordingly, researchers addressed the weathering mechanisms induced by salts (primarily Na2SO4), the stresses generated in the host material, and the durability of ornamental and dimension stones. This study investigates the behaviour

3D-printed (3DP) analogs of natural rocks have been used in laboratory tests concerning geomechanical and transport properties. Rock analogs manufactured by 3D printing can be used to manufacture batch of the samples with specified heterogeneity compared to natural rocks. Rock analogs were manufactured with silica sand (SS) and gypsum powder (GP) using binder jetting as well as with coated silica beads

Before a coal mining operation, it is necessary to carry out coal-bed methane (CBM) pre-extraction to prevent coal and gas explosions, causing accidents. However, gas extraction and coal mining will lead to coal damage, which results in a change in the gas migration law. Especially, under deep mining conditions, the gas migration mechanism is more complicated owing to a high ground temperature. Coal

The primary objective of this work is to improve our understanding of the scale effect of the joint shear behavior. Attempts are made to combine different proposed methods with the multiscale joint shear test. First, a new type of rock-like material made from a mixture of raw materials is used to simulate rock joints. Then a new sampling method is used with the progressive coverage statistical method

A phenomenological model for percussive drilling systems is proposed in this paper to explain the experimentally demonstrated existence of an optimal weight-on-bit (WOB), for which the rate of penetration (ROP) is maximized. Several hypotheses have been previously proposed to explain this universal characteristic of percussive drilling, including increased wear of the bit, reduced indexing, and poor

The strength of rock under combined compression and shear loading has been paid more and more attention, but still lacks a theoretical model that incorporates both compression–shear characteristics and influence of dip angle to estimate the strength of the rock. This work is aiming to solve the issue by combining experimental and theoretical methods. First, in the laboratory, 112 rock samples with

Deep mining and drilling activities typically trigger significant deformation of coal/rock roadway and even coal/rock dynamic hazards, which has attracted considerable attention. Hence, in this article, the mechanics and failure properties of intact coal are examined through triaxial compression tests and creep tests. First of all, triaxial compression experiments demonstrated that the complete stress–strain

In this paper, the microscopic mechanism of crack evolution in brittle material containing 3-D embedded flaw is investigated. The crack evolution mode of 3-D flaw is summarized by the uniaxial compression experiment first. Based on experiment results, the micro-parameters in the flat-joint model are calibrated and numerical models containing 3-D embedded flaw are established in PFC3D. Then, the numerical

The phenomenon of electromagnetic radiation (EMR) generated by rock fracture is relatively common. Due to different properties of rock, the variation laws and distribution characteristics of signals in time and frequency domain are significantly different. In this paper, the uniaxial compression experiments of four different kinds of rocks were carried out under the same loading conditions. EMR response

The bedrock of hydropower stations is susceptible to irreversible failure due to dynamic unloading and loading related to earthquakes, rock bursts or blasting. To ensure operational safety, the damage evolution process of bedrock under cyclic loading must be investigated. Hence, this study investigates the mechanical properties and acoustic emission (AE) characteristics of the bedrock from different

Rockbursts are some of the most dangerous phenomena encountered in underground mines. They can be triggered by an abrupt ground disturbance from a remote seismic source. In this paper, the mechanism of remotely triggered rockbursts around a coal mine drift is analyzed using the synchro-squeezing transform (SST) method and dynamic modeling. Based on seismic monitoring data, the seismic waveform at the

The ground subsidence induced by salt mining has been causing significant damage in Tuzla, Bosnia and Herzegovina since the 1950s. Several investigations and geodetic surveys have been conducted, i.e., traditional topographic surveys (1950–2003) and static GPS surveys (2004–2007). The last GPS survey (2006–2007) revealed that the subsidence in Tuzla was still occurring at a rate of about − 10 cm/year

One of the most important challenges in horizontal well fracturing is to create multiple tightly-spaced hydraulic fractures (HFs) within each fracturing stage in tight reservoirs, especially with the strong heterogeneity. This study explores the influences of static fatigue and pressure shock on the simultaneous initiation of multi-HF from an open-hole horizontal wellbore in a formation with the variability

The failure mechanism of anti-dip layered slopes is essentially different from that of dip layered slopes. Therefore, it is important to investigate the failure mechanism of anti-dip slopes due to excavations. In this study, slope instability induced by mining excavation at the Changshanhao open-pit mine in Neimenggu province, China, was used as a case study. Based on the similarity ratio theory, a

Previous studies on the strength and deformability of pillars in hard-rock mines have demonstrated that the influence of natural fractures diminishes with increasing pillar width. Jointing conditions and fracture intensity/intersections play a critical role in the behaviour of slender pillars (width-to-height ratio less than 0.5). An important challenge is the characterization of rock mass damage as

In underground mining practice, the rock bolt support system is the major support pattern to control the deformation and stability of openings. A rock bolt is generally subjected to complex loads including tension, torsion, bending and shear, which result from the deformation of excavations and exposure to dynamic loads that are generated by rockbursts. An understanding of the response of rock bolt

Columnar jointed basalt is widely distributed in the dam foundation and underground cavern of the Baihetan hydropower station, in which columnar jointing and microfractures are developed, the integrity of the rock mass is poor, and the material easily relaxes after excavation. Therefore, it is important to obtain the real mechanical parameters of columnar jointed basalt in rock mechanics problems.

A comprehensive understanding of the physico-mechanical behavior of rocks in hot dry rock (HDR) reservoir after different stimulation treatments is essential for the safe and effective exploitation of geothermal energy. In this study, the physico-mechanical properties of high-temperature granite (25–600 °C) subjected to slow cooling, water cooling, and liquid nitrogen (LN2) cooling were experimentally

A particle-based discrete element model combined with digital image processing to take into account the grain geometry and size distribution is used to investigate the mechanical and microcracking behavior of Beishan granite (BG), a typical crystalline rock potential for nuclear waste disposal in China. First, the procedure to construct a digital image-based grain-based model is introduced. The unsupervised

The area ratio content of the asperities with different apparent dip angles is studied based on Grasselli’s apparent dip angle distribution function. An approximate expression of the minimum dip angle of the asperities in contact is further obtained according to the contact theory. For regular joints, the peak dilation angle is the average dip angle of all asperities on the contact part. Extending

Seismic disturbances frequently trigger or induce violent strainbursts, threatening regular operations and personnel safety in deep underground excavation. We reproduce the cyclic disturbance-induced strainburst, i.e., the strainburst under combined high static stress and cyclic disturbance conditions in the laboratory using a true triaxial testing system with a relatively low stiffness, where the

Underground mines use a combination of rock reinforcement and surface support elements to maintain the structural integrity of excavations in rock. The design of an effective ground support system requires an understanding of the mechanical behaviour of individual ground support components and how they interact under load. This paper reviews the mechanical behaviour of welded wire steel mesh routinely

Geometry of a single fracture has significant influence on the fluid flow in fractured rocks. However, quantification of geometry–flow relationship in a rock fracture is still far from being completed. The primary goal of this study was to identify a few key geometric parameters for quantifying its impact on fluid flow in a single rock fracture and then to evaluate its hydraulic conductivity. The concept

Muography is a novel imaging method using natural cosmic-ray radiation for characterising and monitoring variation in average material density in a diverse range of objects that cannot be imaged by conventional imaging techniques. Muography includes muon radiography and muon tomography. Cosmic-ray-induced muons were discovered in the 1930’s, but rapid development of both muographic techniques has only

A water curtain system is widely adopted in the underground storage of gas/oil in unlined rock caverns to maintain a stable groundwater level and ensure a good water sealing condition for the storage facility. Hydrogeological tests were conventionally carried out in practice to assess the hydraulic conductivity of the surrounding rocks and evaluate the performance of the water curtain system. Among

Microwave irradiation has been considered as a potential method for weakening rock in mining and civil engineering applications, and numerous studies have demonstrated the strength-reducing effects. SEM-based automated mineralogy provides new opportunities to examine the mineralogical controls on microwave-induced cracking. This study employed a combined approach of optical microscopy and automated

When a rock mass shears along a structural plane, the shear resistance of the structural plane is affected by the structural plane undulations and by the friction between the contact regions. During an earthquake, the seismic load (composed of the cyclic and dynamic loads) produces a dynamic deterioration of the mechanical properties of the structural plane, which is mainly reflected as follows: (1)

The instability of rock slopes and underground engineering structures is usually caused by shear sliding along discontinuities, such as joints or faults, which are usually non-persistent. It is important to study the shear failure behavior of non-persistent joints to better understand the instability mechanism of jointed rock masses. In this research, rock-like samples containing multiple non-persistent

This study examines the effect of variations of the rock property and TBM parameters on the cutter failure. A new disc cutter wear model is developed by coupling Archard’s model and TBM cutter kinematics. The rock property and the TBM parameters are modelled as anisotropic cross-correlated log-normal random fields. The proposed model with a discretized algorithm allows a quantitative evaluation of

Determining stability, quantifying planned dilution, and estimating the potential dilution associated with hangingwall overbreak are critical in the process of stope design in sublevel open stoping mines. To satisfy these objectives, empirical stability graphs and numerical modelling are currently used in the mining industry. Empirical methods are limited to the database used to calibrate them. In

The strength of a rockbolt is one of the key parameters for the design of ground support systems. However, published mechanical performance data by suppliers are usually limited to tensile strength and elongation. To provide additional performance measures, mechanical tests on four commercially available solid reinforcing bar rockbolts have been performed and analysed. In each of the cases, the rockbolts

Majority of the world's mine production is made by surface mining facilities for various reasons. Use of explosives is the most economical way in loosening of the main rock where hard rock formations exist. The degree of fragmentation affects the subsequent excavation and loading operations as well as indicates the success of the blasting process. Although the most preferred method for the measurement

A large amount of lining cracks, pavement uplift and cable trench overturning occurred during the operation of the Dugongling tunnel, which finally led to the closure of the whole line. The study on the lining cracking mechanism is very important to ensure that the tunnel opens again early. First, the actual cracks of the lining were investigated in the field. According to the geological data, the

Comprehensive knowledge and analysis of in situ rock strength and geo-mechanical characteristics of rocks are crucial in hydrocarbon and mineral exploration stage to maximize wellbore performance, maintain wellbore stability, and optimize hydraulic fracturing process. Due to the high cost of laboratory-based measurements of rock mechanics properties, the log-based prediction is a viable option. Nowadays

The chief characteristic of the caving mining method is that caved ores, surrounded by overlying rocks, are drawn from the drawpoint. And the ultimate objective of investigating the draw problems is to forecast the ore loss and dilution. In this paper, the rolling resistance model in the Particle Flow Code was used to simulate the effect of actual shape of different materials flowing towards a drawpoint

Local topography and structural features of discontinuities have a great effect on the movement characteristics and failure mechanisms of the unstable rock blocks of the rock slope. By taking full advantage of the geometric information contained in the multi-temporal terrestrial laser scanning (TLS) point clouds, a technique based on a roto-translation method has been developed to track and monitor

The engineered slopes along transportation routes in the Himalayan region are manifested by multiple sets of discontinuities and are vulnerable to structurally controlled failures. The hazard potential along one such route was assessed by an empirical Q-slope method. The investigated engineered slopes along the route are unstable, and the Q-slope value ranges from 0.0023 to 0.7701. By considering the

The trend today to ever increasing modelling sophistication demands that much more attention be paid by practitioners to achieving better appreciation and characterization of geology and rockmass variability, so that rock–structure interaction effects can be analysed more realistically in better calibrated models. This paper is thus directed towards focussing attention on risk-based geological characterization

Success of a hydraulic fracturing operation depends on the height and width of the induced fractures. One of the critical components controlling fracture size is fracture toughness of the formation. In this work, mode I fracture toughness of Berea Sandstone and Mancos Shale is measured by combining semi-circular bend test (SCB) and digital image correlation (DIC). Experiments were carried out in different

Firmness is one of the most important physical properties of rock, and indicates the rock’s ability to resist damage. It has considerable relevance to mining, blasting, tunneling, construction, and other engineering fields. In this study, the fractal particle-size-distribution theory was used to calculate the surface areas of coal particles after impact crushing. Combining the surface area with the

Laboratory hydraulic fracturing tests on cubic granite specimens with a side length of 100 mm were performed under true triaxial stress conditions combined with acoustic emission monitoring. Six different injection schemes were applied to investigate the influence of the injection scheme on hydraulic performance and induced seismicity during hydraulic fracturing. Three of these schemes are injection

The influence of tectonic, geostatic, and mining stresses on coal and gas outburst (CGO) becomes more obvious with increasing mining depth. The limitations of general experimental methods and test systems hinder the direct observation and characterization of the dynamic responses of the multi-physical parameters associated with CGO. In this study, a custom-made large-scale physical simulation test

Rock breaking using conical picks is a complex process affected by several factors; its performance is directly related to the excavation rate of rock tunnels, which is important in terms of the economic benefits and social impact of a project. This study investigates the effects of cutting depth and water pressure on rock breaking performance using a conical pick assisted by an abrasive water jet

The establishment of spatial correlation among scattering acoustic emission (AE) signals has great potential applied into a deep analysis of triaxial compression behaviors by the AE monitoring technology. Taking the randomly distributed AE signal could as the cube cluster by an introduction of covering strategy from the percolation theory, the quantitative evaluation of spatial correlation instead

Damaged rock mass contains a great number of microstructures and defects at various scales, which could influence wave propagation significantly. In this paper, investigation of low-amplitude stress wave attenuation in rocks with different damage degrees was undertaken to determine the effects of parameters including damage degree, heterogeneity and type of waveforms on wave propagation, attenuation

The impact of blast vibrations on cement-grouted rock is an unresolved challenge in construction projects where blasting is conducted near the grouted areas. This study investigates the blast vibration resistance of cement-grouted rock using both theoretical and experimental approaches. An analytical model is first presented based on structural characteristics and mechanical properties to describe

The anelastic properties of porous rocks depend on the pore characteristics, specifically, the pore aspect ratio and the pore fraction (related to the soft porosity). At high frequencies, there is no fluid pressure communication throughout the pore space and the rock becomes stiffer than at low frequencies, where the pore pressure is fully equilibrated. The models considered here include explicit pore

Rock masses that have a well-defined structure may also present a remarked in situ stress anisotropy; thus, the misalignment of a tunnel with the geostatic principal stresses and/or with the principal axes of material anisotropy is very likely. Analytical solutions for tunnels in transversely anisotropic rock available in the literature assume alignment of the tunnel with the geostatic principal stresses