The Mohr–Coulomb (M-C) and Hoek–Brown (H-B) strength criteria are widely used in various engineering fields, such as mining engineering, tunnel engineering and so on. To investigate the M-C and H-B strength criteria considering the unload...
The Kaiser effect reflects the memory of the loaded rock to the irreversible damage and deformation. The stress level, loading rate and lithology are the main factors affecting the Kaiser effect of the rock. To identify the accurate stress point of t...
Aiming at the large deformation instability problem caused by the excavation unloading of a coal roadway in deep-buried slowly inclined jointed rock mass, the geomechanical parameters and deformation failure characteristics of an engineering geomecha...
Coal seam cavitation is one of the most effective techniques for gas disaster control in low-permeability coal. Due to the difference in cavitation method and process, the damage degree and fracture development range of the coal body around the caver...
During the formation of deep rock bodies, such as hot dry rock, they are frequently exposed to high temperatures and repeated stress perturbations. The prolonged interaction of these two factors is a potential cause of deep underground rock instabili...
Since the turn of the 20th century, glacial thinning has been exposing volcanic mountain slopes around Iceland’s outlet glaciers. In the early 2000s, several slope instabilities appeared around the Svínafellsjökull outlet glacier in...
Skeletal muscle abnormalities and atrophy during unloading are accompanied by the accumulation of excess calcium in the sarcoplasm. We hypothesized that calcium accumulation may occur, among other mechanisms, due to the inhibition of sarco/endoplasmi...
To study the formation mechanism of the lower shaft resistance of uplift piles compared to compression piles, the additional stress caused by uplift and compressive piles in the soil is obtained through indoor model tests with embedded micro earth pr...
The weakening effect is one of the most important causes triggering large deformation and failure of soft-rock engineering; however, few studies paid attention to damage evolution and constitutive relationship of rock in tensile damage in the excavat...
Under specific temperature and strain rate conditions, certain materials, such as low-carbon steels and select magnesium and aluminum alloys, experience a localized deformation phenomenon known as the Lüders effect. This behavior manifests as a...
We utilised a ground-based microgravity hindlimb unloading (HU) mouse model to elucidate the gut microbiota bacterial changes in mice under a simulated microgravity environment. Four-month-old, male C57/Bl6 mice were randomly divided into ground-base...
This paper investigates the impact of surcharge/unloading at both sides of the ground surface on an existing underground shield tunnel at varying burial depths. A large-scale indoor model experiment was conducted to study the vertical convergence def...
Wound healing is a very complex process that allows organisms to survive injuries. It is strictly regulated by a number of biochemical and physical factors, mechanical forces included. Studying wound healing in space is interesting for two main reaso...
The modeling of cyclic behavior in rock remains a challenge due to complex deformation characteristics. This paper studied the mechanical behaviors of granite samples under uniaxial cyclic loading and unloading through cyclic compression tests and ac...
In order to study the influence of advancing speed and stoping time of a coal face on the scale and frequency of rock burst, the energy release characteristics of an overburden fracture under six advancing speeds and four stoping times are studied by...
In the seismic response analysis of liquefiable sites, the existing soil dynamic constitutive model is challenging to simulate saturated sand’s post-liquefaction deformation, and the current pore-water pressure buildup model cannot reflect the...
The aim of the study was to understand the changes of ultrasound-wave speed (US) and acoustic emission (AE) as a result of soil loading and unloading. The soil was dune Sand, Poorly graded, i.e., “SP” according to the Unified Soil Classification Syst...
The construction process of pile foundations can significantly disrupt the soil. Therefore, it is necessary to limit the degree of soil disturbance caused by pile foundation construction to an acceptable level. This paper examines the disturbance eff...
Traditional physical similarity simulation methods struggle to replicate the cumulative unloading–expansion effect in overburden, particularly due to inherent limitations in representing the bulking–compaction behavior of fractured rock m...
For the effect of two-sided sudden surcharge/unloading on existing shield tunnels, an indoor dimensional reduction model test was conducted at a scale of 1:15.5, measuring the ground settlement, lateral convergence of the shield tunnel, and additiona...
Percutaneous ventricular assist devices are utilized in cases of cardiogenic shock following acute myocardial infarction (AMI). However, the mechanism underlying the beneficial effects of LV unloading in AMI remains unclear. This study aimed to exami...
The mechanical behavior of rocks under loading conditions depends on stress path and magnitude. With increasing load, rocks have an elasto-plastic behavior. Within the loading yield surface, constitutive models assume that rocks behave elastically an...
Loading and unloading stress paths play critical roles in investigating the deformation and failure of roadway excavation. In this study, tests under four different loading and unloading stress paths were conducted on red sandstone samples, with the...
After conducting true triaxial tests on sandstone in a laboratory setting, this study aims to determine the safe tunnelling rate of the roadway by examining the instability and failure characteristics of surrounding rock under different disturbance s...
In this study, the response mechanism between macro- and microscales of deep hard-rock diorite is investigated under loading and unloading conditions. Moreover, the statistical theory is combined with particle flow code simulations to establish a cor...
Timely and complete replication of the genome is essential for life. The PCNA ring plays an essential role in DNA replication and repair by contributing to the processivity of DNA polymerases and by recruiting proteins that act in DNA replication-ass...
In most mammals, postural soleus muscles are involved in the maintenance of the stability of the body in the gravitational field of Earth. It is well established that immediately after a laboratory rat is exposed to conditions of weightlessness (para...
Heterostructured materials such as metallic laminates (LMCs) can be specifically tailored to showcase significantly increased mechanical behavior based on the hetero-deformation-induced (HDI) strengthening effect caused by the co-deformation at the v...
25 September 2021
The purpose was to investigate the effect of load and fatigue on landing forces and mechanics. Thirteen Department of State special agents first completed drop jump testing, a maximal treadmill test, and another round of drop jump testing. During dro...
A series of freeze–thaw cycling tests, as well as cyclic loading and unloading tests, have been conducted on nodular sandstones to investigate the effect of fatigue loading and freeze–thaw cycling on the damage evolution of fractured sand...
This paper addresses the flexible flow shop scheduling problem with unloading operations, which commonly occurs in modern manufacturing processes like sand casting. Although only a few related works have been proposed in the literature, the significa...
The aim of this work was to investigate the evolution of the mechanical integrity of the selected offshore oil reservoir during its life cycle. The geomechanical stability of the reservoir formation, including the caprock and base rock, was investiga...
Claystone is potentially the main rock formation for the deep geological disposal of high-level radioactive nuclear waste. A major factor that affects the deformation of the host medium is effective stress. Therefore, studying the effective stress pr...
Conventional and cyclic unloading tests with different unloading rates were conducted to study the influences of unloading patterns and rates on the deformation characteristics and mechanical properties of tectonic coal. The results demonstrate that,...
Shale reservoir has an initial unloading effect during the natural uplift and erosion process, which causes the shale brittleness to change, affecting the design of the fracturing scheme. To consider this, the axial compression loading and confining...
Consolidated undrained triaxial shear tests were performed on undisturbed saturated structured clay at three unloading rates (0.1, 0.25, and 2.5 kPa/min) using a GDS triaxial system to determine the effects of different unloading rates and unloading...
This paper utilizes the waste bunker of a waste incineration plant as the analysis model. It analyzes the airflow characteristics under various unloading door opening states and the air flow velocity through CFD simulation. The simulation analysis re...
Protective seam mining is the most economical and effective measure for eliminating coal and gas herniation. To study the unloading effect of the mining of a protective seam on the protected layer, and to better grasp the effect of the protective lay...
Rubber composites are hyperelastic materials with obvious stress-softening effects during the cyclic loading–unloading process. In previous studies, it is hard to obtain the stress responses of rubber composites at arbitrary loading–unloa...
The quality of excavated and unloaded rock masses on steep and high slopes in cold regions is prone to deterioration, which in turn affects the long-term stability and safety of excavated slopes. Based on a triaxial unloading-damage test of sandstone...
This article describes the influence of dynamic bridging in the unloading of a hopper at a processing plant on the grain flow homogeneity in a convective-microwave zone. In accordance with calculation methods for unloading hoppers, the parameters of...
Insufficient stress response and elevated oxidative stress can contribute to skeletal muscle atrophy during mechanical unloading (e.g., spaceflight and bedrest). Perturbations in heat shock proteins (e.g., HSP70), antioxidant enzymes, and sarcolemmal...
To investigate the seepage and deformation failure characteristics of deep unloaded rock mass under cyclic loading and unloading disturbance, a series of triaxial cyclic loading and unloading tests were conducted on granite. These tests were performe...
The optimization of film-unloading and film–soil separation components can effectively improve the residual film unloading rate and reduce impurity content. So, the DEM models of soil and residual film were established and the suspension and fl...
Low-intensity pulsed ultrasound (LIPUS) has been proved to promote the proliferation of myoblast C2C12. However, whether LIPUS can effectively prevent muscle atrophy has not been clarified, and if so, what is the possible mechanism. The aim of this s...
The unclear understanding of the mechanical behavior of soil under unloading conditions is a significant reason for the frequent occurrence of accidents and difficulties in the deformation control of foundation pit engineering in coastal areas. This...
The creep associated with unloading surrounding rock during the excavation of deep tunnels seriously affects the stability of the tunnel, and a high seepage pressure will aggravate the strength attenuation and structural deterioration of the surround...
To address loading and unloading issues in civil and hydraulic engineering projects that employ coarse-grained soil as fill material under plane strain conditions during construction and operation, cyclic loading–unloading large-scale plane str...
3-D particle-based discrete element method (PB-DEM) was employed to numerically study the mechanical and progressive failure characteristics of pre-fissured marble specimens under conventional triaxial unloading conditions. The microscopic parameters...
The paper represents a test investigation of the mechanical properties and acoustic emission (AE) characteristics of low-strength coal specimens subjected to cyclic loading and unloading. From the lab tests, the following conclusions can be obtained:...
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