Mostafa Sharifzadeh

Phase aberration is one of the primary sources of image quality degradation in ultrasound, which is induced by spatial variations in sound speed across the heterogeneous medium. This effect disrupts transmitted waves and prevents coherent summation of echo signals, resulting in suboptimal image quality. In real experiments, obtaining non-aberrated...

Energy-absorbing rockbolts have been widely adopted in burst-prone excavation support, and their serviceability is closely related to the frequency and magnitude of seismic events. In this research, the split-tube drop test with varying impact energy was conducted to reproduce the dynamic performance of MP1 rockbolts under a wide range of seismic e...

Empirical pillar design methods are commonly used in the mining industry. The parameters within which these methods are valid are frequently unknown to the user or ignored. In addition, empirical design may not consider essential parameters such as blasting effects, orebody dip and the presence of geological structures, which all adversely affect t...

Brittle failure of rock is characterized by the initiation, propagation and coalescence of micro- and macro-cracks. To study the macro-crack evolution of rocks, a parallel long strain gauge measurement apparatus was developed, which was composed of multiple long axial strain gauges and linear variable differential transformers (LVDTs). Using the de...

Layered rocks usually show anisotropy in their deformation and failure characteristics. The anisotropy is mainly caused by the orientation of thin-layered structure (e.g., bedding or foliation). Thin-layered structures are likely to fail, thus jeopardizing the stability of underground excavations. Under different bedding or foliation orientations,...

While accuracy is an evident criterion for ultrasound image segmentation, output consistency across different tests is equally crucial for tracking changes in regions of interest in applications such as monitoring the patients’ response to treatment, measuring the progression or regression of the disease, reaching a diagnosis, or treatment planning...

In the challenging environment and dynamic topology of an underground mine, reliable and effective communication is a high-stakes issue. Automation by remote and automated systems has resulted in enhanced real-time response to events and improvements in employees’ workplace health and safety, operational management, energy efficiency, and cost-effi...

In recent decades, mining projects have required deeper excavations to access resources due to increased excavating depth, the risks of mining operations, and rockburst increase. As an important line of defense, ground control measures and burst-resistant rock support are used to prevent or minimize excavation damage and thus enhance workplace safe...

The design of landfill liners of waste disposal to reduce migration of leachate containment, low swelling, and shrinkage and ensure sufficient shear strength to resist bearing capacity and instability of the landfill has been a major challenging task to landfill engineers. Over the last decade, there has been an increase in research on the stabilit...

Circumferential yielding lining is able to tolerate controlled displacements without failure, which has been proven to be an effective solution to large deformation problem in squeezing tunnels. However, up to now, there has not been a well-established design method for it. This paper aims to present a detailed analytical computation of support cha...

A novel method is presented that is capable of more accurately extracting rock surface features based on the geometrical characteristics of a 3D point cloud obtained from a survey. The core feature of the algorithm is a newly established method that can provide a robust estimation of point normals, while excluding statistical outliers from the calc...

The performance of ultrasound elastography (USE) heavily depends on the accuracy of displacement estimation. Recently, Convolutional Neural Networks (CNN) have shown promising performance in optical flow estimation and have been adopted for USE displacement estimation. Networks trained on computer vision images are not optimized for USE displacemen...

Ignoring the shotcrete hardening property in tunnel design may lead to an overestimation of the bearing capacity of shotcrete liners and underestimation of tunnel convergence. However, accounting for this non-linear hardening behavior of shotcrete in the tunnel analytical model is difficult because of the complexity of the mathematical derivation....

The performance of ultrasound elastography (USE) heavily depends on the accuracy of displacement estimation. Recently, convolutional neural networks (CNNs) have shown promising performance in optical flow estimation and have been adopted for USE displacement estimation. Networks trained on computer vision images are not optimized for USE displaceme...

The Higashi-Shikagoe limestone quarry is an open-pit mine situated in Hokkaido Prefecture, Japan, that has experienced four slope failure incidents since 1996. The rock slope behaviour has been monitored since the first failure event by measuring the rock slope surface displacement using an automated polar system. Recent measurements have revealed...

A common issue in exploiting simulated ultrasound data for training neural networks is the domain shift problem, where the trained models on synthetic data are not generalizable to clinical data. Recently, Fourier Domain Adaptation (FDA) has been proposed in the field of computer vision to tackle the domain shift problem by replacing the magnitude...

Convolutional neural networks (CNNs) have attracted a rapidly growing interest in a variety of different processing tasks in the medical ultrasound community. However, the performance of CNNs is highly reliant on both the amount and fidelity of the training data. Therefore, scarce data is almost always a concern, particularly in the medical field,...

The rock slope stability analysis can be performed using deterministic and probabilistic approaches. The deterministic analysis based on the safety concept factor uses fixed representative values for each input parameter involved without considering the variability and uncertainty of the rock mass properties. Probabilistic analysis with the calcula...

While accuracy is an evident criterion for ultrasound image segmentation, output consistency across different tests is equally crucial for tracking changes in regions of interest in applications such as monitoring the patients' response to treatment, measuring the progression or regression of the disease, reaching a diagnosis, or treatment planning...

Underground excavation designs in mining and civil engineering projects are associated with a different geometric, complex ground structure, field–stresses, and groundwater conditions. Due to diverse influence factors and various requirements for each project, the design procedure should be customised based on the site-specific factors. The design...

High stress concentrations around underground excavations can result in significant damage to deep hard-rock mines. These conditions can be the result of stopping activities, blasting, seismicity, or other mining activities. Large anisotropic deformation and excavation closure, especially under high-stress conditions , are expected if the excavatio...

Appropriate rock characterization is beneficial in providing a reliable judgment on rock properties which is crucial for the design process of rock engineering applications. However, it can be difficult to obtain consistent mechanical parameters due to substantial variations in rock properties. In this research, uniaxial compression tests on doleri...

As mining depth extends continuously, complex geological environment and strong mining stress pose serious challenges against excavation safety and higher demand for bolt support. To meet the challenges, a new type of flexible bolt is developed that is free from the limitation of excavation height and can be installed quickly. The flexible bolts ha...

Deep mining and the related dynamic loading are the critical challenges confronting the reinforcement system like energy-absorbing rockbolts, which plays a decisive role in the dynamic response of underground mine excavations. Over the past decades, various types of novel energy-absorbing rockbolts with different deformation mechanisms and dynamic...

Deep mining and the related dynamic loading are the critical challenges confronting the reinforcement system like energy-absorbing rockbolts, which plays a decisive role in the dynamic response of underground mine excavations. Over the past decades, various types of novel energy-absorbing rockbolts with different deformation mechanisms and dynamic...

Determining the residual frictional properties of rock discontinuities in detail is crucial for the design of safe rock structures. In this paper, direct shear experiments were conducted on two types of artificial limestone joint samples (rough standard tensile joints and grinded planar small joints). The primary goal of this study is to compare th...

Diesel particulate matter (DPM) is carcinogenic to humans. Underground miners have a high risk of over-exposure to high concentrations of DPM. To control DPM effectively, it is essential to understand the DPM dispersion characteristics. In this study, the DPM distributions of three key and representative mining activities, shotcreting, charging and...

Rock Quality Designation (RQD) is a parameter used in rock mass classification systems defined as "the percentage of sound drill core with spacing of more than 10 cm". Due to its simplicity, RQD is collected by many mining operations, and correlations between large deformation ground behaviour and RQD (or bedding spacing) have been attempted. Even...

In a natural condition, temperature variations and phase transition of pore water are the two most effective factors on the mechanical properties of rocks. Instabilities occurred as a result of climate changes, highlight the importance of rock characteristics. This paper conducted a laboratory investigation to study the temperature-dependent mechan...

Extreme ground behaviour in high-stress rock masses such as rockburst prone and squeezing ground conditions are encountered in a range of underground projects both in civil and mining applications. The occurrence of such ground behaviour types are difficult to predict and special design and construction measures must be taken to control them. Deter...

The effect of cyclic loading on the fatigue life, deformation properties and damage mechanisms of two microstructurally different rock types is explored by conducting uniaxial monotonic and cyclic compression tests under different loading conditions. Results show greater damage effects of low-frequency cyclic loading on the crystalline rock than on...

The response of rock mass to engineering activities related to environment greatly depends on the scale of rock mass. Therefore, the scale dependency of rock mechanical behavior under different rock mass conditions is investigated in this research. As a crucial parameter, the volume of the block provides a fundamental understanding to define the ro...

The micro-structures of rock govern meso- and macro-scale rock behaviours and their failure mechanisms. This paper applied the experimental study (uniaxial and triaxial compressive tests) and scanning electron microscope (SEM) method to illustrate the relationship between microscopic damage and mesoscopic fracture. Specifically, this study carried...

Extraction of geothermal energy, oil and gas, and coalbed methane (CBM) are all constrained by the rock’s permeability. To stimulate the production, hydraulic fracturing has become a routine procedure, which is influenced by many factors especially the pre-existing natural fractures. The natural fractures have various characteristics, such as apert...

In the challenging environment and Cutting-edge technology in mining industry, reliable and effective communication is a high-stake issue, along with the objectives of safe and efficient underground mining operations. Automation through remote and automatic systems has delivered improvements in workplace health and safety for employees, operational...

One of the main sources of image degradation in ultrasound imaging is the phase aberration effect, which imposes limitations to both data acquisition and reconstruction. Phase aberration is induced by spatial changes in sound velocity compared to the default values and degrades the quality of beam focusing. In addition, it prevents received channel...

A computational code has been developed based on finite-volume method (FVM) to investigate fluid flow-through rough-walled rock fractures during shear processes, considering evolutions of aperture and contact area with shear displacement. In the code, the full 3-D Navier–Stokes equation is solved in a cell-centered collocated variable arrangement a...

Energy principles, which can favorably explain the complete rock failure process, are one of the most reliable analysis approaches in rock mechanics and engineering. In this study, a strain energy approach under true triaxial compression (TTC) is proposed. On this basis, the energy evolution characteristics and variations of different failure behav...

به دلیل پیشرفت¬های زیادی که در زمینة دانش مهندسی سنگ طی دهة اخیر رخ داد، بسیاری از کتب قدیمی مکانیک سنگ که توسط اساتید برجسته در سطح دنیا چاپ شده بود، مورد تجدید نظر و چاپ مجدد قرارگرفته و مطالب مفیدی به آنها افزوده شد. جهت همگام سازی دانش بومی در زمینة مذکور، مؤلفین برآن شدند تا تجارب حرفه¬ای و تحولات جدید را با دانش پیشین تلفیق نموده و در قالب یک...

Underground excavations are naturally under deteriorating environments due to corrosive ground water, type of minerals, and rock mass structures. The abundant of water (e.g., humidity and the inflow of groundwater), and the presence of chemical materials are among the main reasons creating such environments. Rock formations also contain minerals, w...

In order to reduce the stress on the underlying coal seam and improve mining efficiency in deep coal mining activities, narrow coal pillars are often used. They are the main factor that increases the risk of coal spontaneous combustion in the goaf. Based on the on-site experiment and the experimental analysis in the laboratory, this paper adopted c...

Stability of tunnels in stratified rock masses under low stress conditions is governed by the rock mass structure (blocks) and excavation geometry and dimension. A physical model was built and the effects of bedding dip, discontinuity spacing, and tunnel dimensions on tunnel failure mechanisms were examined. Based on the image analysis, three zones...

Ore deposits are expected to be permeable (e.g. porous media) to grant the success of In-situ recovery (ISR). However, the ISR from hard deposits which lack of porous media is still challenging, due to poor understanding of the fracability i.e. connectivity between pre-existing and artificial fractures. Therefore, in this study, extremely hard Foli...

The energy evolution processes and mechanisms between three hard rocks are studied using a strain energy analysis method under true triaxial compression (TTC). Using Beishan granite as an example, the change in the energy storage limit Umaxe, strain energy ratio and strain energy conversion rate for different σ2 and σ3 values is investigated. The r...

Development of deep underground mining projects is crucial for optimum extraction of mineral deposits. The main challenges at great depth are high rock stress levels, seismic events, large-scale deformation, sudden failures and high temperatures that may cause abrupt and unpredictable instability and collapse over a large scale. In this paper, a gr...

The study of rock fracturing is a fundamental research topic in rock mechanics and engineering. In this paper, based on complete stress–strain curves obtained under TTC and the corresponding AE and strain energy results, the mechanical properties and fracturing process of Beishan granite are studied. A representative test result (σ2 = 75 MPa, σ3 =...

The stability analyses of slope excavations in rock mass require reliable geomechanical input parameters such as rock mass strength, friction angle and cohesion of sliding surface. These parameters are naturally uncertain and their exact values cannot be known, therefore, their variability must be properly accounted for in the stability analyses. D...

Underground excavations are naturally under deteriorating environments due to corrosive ground water, type of minerals, and rock mass structures. The abundant of water (e.g., humidity and the inflow of groundwater), and the presence of chemical materials are among the main reasons creating such environments. Rock formations also contain minerals, w...

Fractures play a crucial role in earth resource engineering, such as geothermal exploitation, coalbed methane (CBM) extraction, and hydraulic fracturing. Breaches, as main channels of fluid flow, have various characteristics, such as aperture, density, and persistence that could affect the transmissivity. Due to the difficulty of distinguishing the...

Pillars play a critical role in an underground mine, as an inadequate pillar design could lead to pillar failure, which may result in catastrophic damage, while an over-designed pillar would lead to ore loss, causing economic loss. Pillar design is dictated by the inclination of the ore body. Depending on the orientation of the pillars, loading can...

Discontinuities considerably affect the mechanical and hydraulic properties of rock mass. These properties of the rock mass are influenced by the geometry of the discontinuities to a great extent. This paper aims to render an account of the geometrical parameters of several discontinuity sets related to the surrounding rock mass of Rudbar Lorestan...

The low-temperature oxidation of coal during coalbed methane extraction is inevitable. To study the evolution of the CH4 adsorption and desorption characteristics in coal masses during the low-temperature oxidation of coal, starting from the evolution of physical and chemical adsorption of CH4 in coal masses during the low-temperature oxidation of...

Rockbolt is widely employed all over the world as an effective ground reinforcement element in order to secure the underground workplaces. Ordinary encapsulated rebar or rebar rockbolt is most popular and commonly used as reinforcement in a ground support system because of its accessibility, cost effectiveness and easy practicability. Reinforcement...

Laser perforation of oil and gas wells is a new method for well completion as an alternative to blasting methods. Under real perforation in oil and gas wells, three main factors have influence on the laser perforation such as specific energy (i.e., energy required to remove the unit weight of rock). These three factors are temperature, the hydrauli...

Pillar stability is an important factor for safe working and from an economic standpoint in underground mines. This paper discusses the effect of blast damage on the strength of hard rock pillars using numerical models through a parametric study. The results indicate that blast damage has a significant impact on the strength of pillars with larger...

Laser perforation of oil and gas wells is a new method for well completion as an alternative to blasting methods. Under real perforation in oil and gas wells, three main factors have influence on the laser perforation such as specific energy (i.e., energy required to remove the unit weight of rock). These three factors are temperature, the hydrauli...

To improve the extraction efficiency and capacity of coalbed methane (CBM) to the greatest extent possible, this study explores the effects of the internal mechanism of low-temperature oxidation of CBM reservoirs during CBM extraction. The evolution of the porosity and the methane adsorption and desorption characteristics of the coal matrix during...

Underground mining is going to be deeper gradually because near surface resources are going to be depleted. Therefore, risk of seismic events in underground mines is escalating. Additionally, existence of the large ratio of horizontal to vertical stress, could be a potential reason for high-stress condition and occurrence of dynamic activities. Dep...

Rock engineering projects have always been constructed on different (from micro to macro) scales. This makes understanding rock behaviour at different scales essential. In previous statistical studies on igneous hard rocks, the correlation of uniaxial compressive strength (UCS) values in different diameters with estimations of specimen size effect...

The advancement in tunnelling and underground space technologies and the need for large scale monitoring and communication systems for safe and efficient operations has triggered the era of wireless sensor networks (WSNs). The progress of WSNs have been associated with the innovation of sensor nodes with the more significant features of smaller siz...

Quantitative descriptions of geochemical patterns and providing geochemical anomaly map are important in applied geochemistry. Several statistical methodologies (nonstructural and structural) are presented in order to identify and separate geochemical anomalies. Structural methods take the sampling locations and their spatial relation into account...