26 September 2014
Recent research suggests that crack cocaine use alters systemic biochemical markers, like oxidative damage and inflammation markers, but very few studies have assessed the potential effects of crack cocaine at the cellular level. We assessed genome i...
Soft broken surrounding rock exhibits obvious rheological properties and time-dependent weakening effects under the action of deep high-ground stress, leading to the increasingly prominent problem of sustained large deformation in deep roadways. In t...
To explore the potential precursors of rock instability, it is necessary to clarify the mechanism of micro-crack from fracturing to failure, which involves the evolution of fracture size, orientation, source model, and their relationships to the load...
For the failure issue of the weak part of the safety end of the nuclear power pressure vessel connection, the J-integral method was used to test the fracture toughness of the weak part at the bottom of the dissimilar metal welded joints (DMWJs) of SA...
First, a recently developed eigenfunction expansion technique, based in part on the separation of the thickness variable and partly utilizing a modified Frobenius-type series expansion technique in conjunction with the Eshelby–Stroh formalism,...
In order to monitor the crack growth of the wood material better and reduce failure risks, this paper studied the attenuation characteristics of acoustic emission signals in wood through pencil lead breaking (PLB) tests, in the aim of estimating the...
Seepage through construction joints is a major factor affecting uplift pressure and long-term safety of concrete dams. Pre-existing joints with millimeter-scale openings provide preferential flow paths, where hydraulic pressure can induce joint openi...
There remains a lack of systematic understanding of burn-through instability, which also restricts the development of evaluation criteria. Based on the designed test device, the dynamic evolution behavior and failure mechanism of burn-through instabi...
When mineral resources are extracted using underground mining methods in hilly regions, landslides or slope failures can be induced frequently. In this study, slope collapse disasters in mountain mining areas were analyzed. The model test and numeric...
This study examines the stability of the Huangyukou landslide in Yanqing District, Beijing, under varying rainfall conditions, focusing on the effects of rainfall infiltration and surface runoff on slope stability. Using a combination of field survey...
In hilly regions, landslides or slope failures are very common phenomena, when underground mineral resources are excavated. In this study, some landslide disasters in a mountain mining area were analyzed. The engineering geological and instability re...
Rapid excavation in deep rock masses imposes a non-proportional stress path that can destabilize jointed rock. A three-dimensional Particle Flow Code (PFC3D) true-triaxial model of granite containing two parallel non-persistent joints was used to exa...
The external envelope walls of a significant percentage of the residential building stock in Southern European countries is commonly constituted by infill masonry walls. However, thousands of square meters of this masonry wall typology presents sever...
Control of the grouting pressure within the critical grouting pressure for crack propagation in Ordovician limestone can not only ensure grout penetration length, but also prevent the risk of creating an artificial water channel. Based on the fractur...
Rockmass in deep mining is highly susceptible to large-scale collapses under high stress and blast-induced disturbances, leading to casualties and economic losses. To investigate the evolution characteristics of goaf instability and the types of seis...
The deformation and fracture characterization of an Mg−2Sn−1Ca alloy were studied through uniaxial isothermal compression tests. The flow stress curves, the efficiency of power dissipation, the instability parameter and the fracture behav...
To investigate the effect of crack geometry on tensile deformation and strain localization in X46 pipeline steel thin-walled tubes, uniaxial tensile tests were conducted on specimens containing prefabricated cracks with different sizes, types, and or...
During rock failure and instability, cracks usually appear as microcracks in local areas and then expand into significant macroscopic cracks. In this study, the whole process of rock deformation and instability under uniaxial loading is investigated...
With the continuous expansion of the application range of gob–side entry retaining technology, the depth, height, and advancing speed of coal seams also increase, which brings great problems to the stability control of surrounding rock structur...
A new criterion for hydrogen-induced cracking (HIC) that includes both the embrittlement effect and the loading effect of hydrogen was obtained theoretically. The surface cohesive energy and plastic deformation energy are reduced by hydrogen atoms at...
The cracking of rock mass under compression is the main factor causing structural failure. Therefore, it is very crucial to establish a rock damage evolution model to investigate the crack development process and reveal the failure and instability me...
Crack propagation leads to rock instability and failure, which seriously influence the safe and efficient operation of coal mines. According to the characteristics of fracture development and expansion, this paper takes a fractured rock with differen...
This study presents a multiscale numerical simulation of the behavior of crack growth in the heat-affected zone (HAZ) of AH36 marine steel welded joints under fatigue loading from the micro-scale to the macro-scale. The MD-FEM method and the multisca...
A fatigue test on the failure mode of flange shafts was conducted. The propagation characteristics of the initial crack at the junction between the shaft and the flange as well as its angle effect were studied. This study developed an analysis progra...
During the process of rock deformation and failure, a significantly large number of charge signals are generated as a result of fracture appearance and crack expansion. The generation of charge signal is the comprehensive embodiment of the coal-failu...
In lignite open-pit mines, the blasting mining method and large-scale mechanical shovelling processes induce substantial cyclic disturbances in coal seams at the terminal slope during lignite extraction, significantly increasing the risk of slope des...
The rock mass is susceptible to instability and damage during cavern construction. The blast-induced cracking process of the rock mass contains a wealth of information about the precursors of instability, and the identification of fracture nucleation...
Ultra-large underground metal mines often have complex surrounding rock structures, making traditional assessment methods inadequate for warning against the sudden failure of highly brittle rock masses. To accurately identify high-risk rock layers, t...
In cold-region rock engineering, freeze–thaw cycle-induced crack propagation in fractured rock masses serves as a major cause of disasters such as slope instability. Existing studies primarily focus on the influence of individual fissure parame...
The susceptibility of structural concrete to early-age cracking depends on material composition, methods of processing, structural boundary conditions, and a variety of environmental factors. Computational modeling offers a means for identifying prim...
The effect of a biaxial load on brittle fractures of solids under predominantly elastic deformation and mode I loading conditions is studied in this article. A cross-shaped specimen is used in this work, and the variation of T-stress is achieved by c...
The propagation and coalescence of cracks in fiber-reinforced concretes (FRCs) is the direct cause of instability in many engineering structures. To predict the crack propagation path and failure mode of FRCs, an orthotropic-bond-based peridynamic (P...
Advanced ceramics, such as alumina and zirconia, are widely used in modern industries, due to their superior properties, such as high hardness and strength. Fracture toughness is a significant property that describes the capability of materials to re...
Anchored surrounding rock is prone to large nonlinear deformation and instability failure under dynamic disturbances. The fissures and defects within the surrounding rock make the rock mass’s bearing characteristics and deformation instability...
The water immersion of surrounding rock slide surface causes lining cracking of the shallow buried loess tunnel, and different types of slide surface and different immersion degrees have different effects on secondary lining. In this paper, four type...
This study is concerned with the nonlinear free vibration of a cracked functionally graded porous cylindrical panel reinforced with graphene platelets by introducing a phase-field crack model. Conventional crack modeling by separating the grid nodes...
Understanding the mechanical behavior of pre-cracked rock masses is essential for assessing geohazards in deep mining. This study combines laboratory experiments and numerical modeling to investigate the effects of double-crack inclination angles on...
Investigating crack evolution characteristics in expansive soil under dry–wet cycle conditions is essential for analyzing the shallow instability of embankments and roadbeds filled with this type of soil. Indoor tests on remolded expansive soil...
A dynamic disturbance will induce cracks around the tunnel in tunnel blasting or shield construction. To investigate the overall stability of cracks with various angles during a fixed borehole (round hole explosion) blasting, models containing an ind...
Rock failure, which causes instability in rock engineering, is an engineering accident that generally occurs through the coalescence of the preexisting cracks in rocks. Therefore, it is very important to research the coalescence of rock cracks to pre...
Foliation-induced anisotropy in phyllite leads to complex deformation and failure responses, making excavation stability analysis and support design particularly challenging for geo-energy and geo-resource applications. To elucidate the influence of...
Natural cracks are prone to form in toppling deformed rock masses during the toppling process, and these cracks are likely to undergo hydraulic fracturing failure under the action of high water head. This paper leverages the advantage of the extended...
The instability and fracturing of gas drainage boreholes are one of the main causes of low drainage efficiency. Based on the rock mass energy principle and the Barenblatt model, the energy evolution of the coal–rock mass around the hole, the co...
The coal and gas outburst and rockburst coupling disaster is becoming increasingly serious due to deep mining. To clarify the mechanism inducing the outburst–rockburst coupling disaster, a true triaxial single-sided unloading mechanical test wa...
The instability of hard and brittle rock often leads to disastrous consequences in underground engineering. Under various surrounding rock pressure conditions, in situ stress induces corresponding deformation and damage to the floor post-mining. Ther...
In hydraulic fracturing tests, the initial crack length and the compressibility of the injection system have a significant effect on the initiation and propagation of the fracture. Numerical or theoretical models that ignore the compressibility of th...
As temperature changes, red clay is prone to shrink and generate cracks, which weaken the structure and the stability of soil mass, leading to various engineering problems, such as damage and instability in engineering structures. To study the effect...
Mechanics-seepage synchronous tests on gas-bearing coal under three different stress paths were designed and implemented to evaluate how load path affected the mechanical strength and permeability of deep mining-disturbed coal. The cracks-count evolu...
Stress damage of shale during the uniaxial loading process will cause the change of permeability. The study of stress sensitivity of shale has focused on the influence of confining pressure on shale permeability and the change of shale permeability d...
The cracks and holes in underground engineering are the critical factors that cause the instability of the surrounding rock. It is helpful to control the stability of surrounding rock to study the samples with combined defects of cracks and holes. In...
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