The objective was to optimize the existing solution for the limit support pressure of a tunnel face. Firstly, based on the numerical simulation results, the existing three-dimensional analytical solution for pore water pressure distribution is expand...
The stability analysis of the tunnel face is not only essential for guaranteeing the safe construction of urban shallow tunnels, but also directly affecting the influence degree of tunnel construction on nearby structures. The primary concerns in the...
With the rapid development of the tunnels constructed under the rivers and seas, the research on face stability of shield tunnel in water-rich sand has important theoretical value and engineering application significance. In addition to the loads exe...
Accurately estimating the stability of horseshoe tunnel faces remains a challenge, especially when excavating in rock masses. This study aims to propose an analytical model to analyze the stability of the horseshoe tunnel face in rock masses. Based o...
This paper proposes a theoretical model for the stability analysis of a box tunnel face in non-cohesive soils considering the uneven distribution of support pressure caused by multiple cutter heads and screw conveyors. The support pressure distributi...
To study excavation face instability in upward shield tunneling, a 3D numerical model was established using ABAQUS software v2023 under different depth ratios (C/D = 1, 1.5, 2, 3, 4), with reference to the upward shield tunneling project of the Midos...
Based on the nonlinear failure criterion and modified tangential technique, the upper bound solutions of the critical supporting pressure on the deep tunnel face were obtained under pore water pressure conditions. The influence of parameters on the c...
Pipe-jacking construction technology is favored in urban construction due to its advantages of high safety and being a non-excavation technique. However, instability of the tunnel face often occurs due to unfavorable conditions, such as pipe jacking...
In shield construction, the limit support pressure of the tunnel face has an important influence on ground settlement and construction safety. In this study, MIDAS GTS NX software was used to conduct a series of three-dimensional finite element simul...
In the water-rich karst regions, high water and mud outbursts are common geological disasters in tunnel construction. To ensure the safe and smooth construction of tunnel projects, it is necessary to consider anti-water pressure, water inrush prevent...
The tunnel face stability in composite strata, commonly referred to as the soft upper and hard lower condition, is a critical challenge in tunnel construction. The soft–hard ratio (SA) strongly influences the limit support pressure as well as t...
As tunnel excavation under poor geological conditions is liable to cause ground collapses, reinforcement measures are necessary to reduce construction risks. The stability of a tunnel face that was reinforced using horizontal pre-grouting was investi...
This paper presents a review of selected tunnel stability models that have been developed and used in calculating the minimum tunnel face pressure as described by original authors. Furthermore, this paper provides a comparison of required tunnel face...
Existing methods for calculating the ultimate support pressure of tunnel faces do not consider the control of seepage flow. Therefore, a model for calculating the ultimate support pressure under seepage conditions was established based on a two-dimen...
Excavations for underground structures, such as working shafts, underground grain silos, and parking garages, are characterized by uniformity, consistent dimensions, large quantities, and strict timelines. Prefabricated recyclable supporting structur...
According to field observation and theoretical analysis, the failure of the 1523103 reserved roadway is mainly affected by the lateral support pressure, rock mass strength, and support mode. With the mining of the 152309 working face, the lateral pre...
When a temporary support is used to control new surrounding rock in a deep mining roadway, the new surrounding rock is supported by the working resistance of the temporary support. In this study, the influence of deep well boring roadway deformation...
The determination of the ultimate supporting force of the shield excavation face is an important problem to be solved in shield construction. Considering that the tunnel burial depth ratio has a significant effect on the instability mode of the excav...
The aim of this study is to provide a solution for the plastic limit pressure and stress intensity factor of the elbows containing a part-through axial semi-elliptical crack by considering various crack sizes. The supporting system and loading condit...
Laser powder bed fusion (L-PBF) manufacturing technology is an emerging field of research that focuses on evaluating constraints in printed products. This study highlights the importance of considering various factors, such as mechanical properties a...
17 April 2018
This research developed and tested a model of the social contagion effect of coworkers’ safety violations on individual workers within construction crews. Both situational and routine safety violations were considered in this model. Empirical d...
Foot plantar pressure is the pressure field that acts between the foot and the support surface during everyday locomotor activities. Information derived from such pressure measures is important in gait and posture research for diagnosing lower limb p...
When soft rock tunnels pass through fractured fault zones, they are particularly susceptible to extrusion and large-scale deformations, especially during seismic events. To address these challenges, this study introduces an innovative yield-support s...
An increasing number of oil and gas companies reach their economic limit after years of production, exhausting the support of natural-pressure drive mechanisms in the reservoir and the benefits of water or gas injection [...]
Based on the improvement of the Karl Terzaghi failure mode for calculating the surrounding rock pressure of loose rock mass, combined with the upper bound theorem of limit analysis, the formula for calculating the surrounding rock pressure of shallow...
Flexible capacitive pressure sensors with a simple structure and low power consumption are attracting attention, owing to their wide range of applications in wearable electronic devices. However, it is difficult to manufacture pressure sensors with h...
Oxygen transport membranes can enable a wide range of efficient energy and industrial applications. One goal of development is to maximize the performance by the improvement of the material, microstructural properties and operational conditions. Howe...
With the implementation of the regional coordinated development strategy, traffic flow has grown explosively. The construction of a larger tunnel section becomes an effective way to solve the highway network’s insufficient transport capability...
A quantitative stability analysis of a three-dimensional (3D) rectangular cavity crown with limited buried depth in generalized Hoek–Brown (GHB) rock mass is conducted employing the limit analysis approach. A 3D collapse mechanism for a shallow...
The COVID-19 pandemic raised global concerns about the shortage of ventilators and revealed the challenges of rapidly scaling up production to meet emergency needs. In response, numerous teams worldwide attempted to develop emergency and simple mecha...
Ru supported on mayenite electride, [Ca24Al28O64]4+(e−)4 a calcium aluminum oxide denoted as C12A7e−, are described in the literature as highly active catalysts for ammonia synthesis, especially under conditions of low absolute pressure. In this stud...
When tunnels pass through high-stress, weak, and fractured rock layers, conventional rigid supports often struggle to resist the significant loosening pressure and deformation pressure from the surrounding rock, leading to various large deformation d...
We aimed to assess the success rate and facilitators of and the barriers to the implementation of in-shoe plantar pressure measurements in footwear practice for people with diabetes at high risk of foot ulceration. Eleven Dutch footwear practices wer...
The mining and geological conditions in which coal mining is carried out are highly variable, which results in dynamic rock manifestations. These include rock mass dynamic failure (seismicity), causing dynamic impacts and also quasi-static rock movem...
Pressure injury (PI) is a major problem for patients that are bound to a wheelchair or bed, such as seniors or people with spinal cord injuries. This condition can be life threatening in its later stages. It can be very costly to the healthcare syste...
Right-sided mechanical support of the Fontan circulation by existing devices has been compounded by the cross-sectional design of vena cava anastomosis to both pulmonary arteries. Our purpose was to investigate whether increasing inferior vena cava (...
To study the deformation and failure mechanisms of soft rock mining roadways, the 1506 return airway of Anyang Coal Mine is taken as the engineering background. Based on limit analysis theory, a failure model based on a rigid slider system is constru...
The chemical–mechanical polishing (CMP) of silicon wafers involves high-precision surface machining after double-sided lapping. Silicon wafers are subjected to chemical corrosion and mechanical removal under pressurized conditions. The multichi...
Objective: To assess the school breakfast program (SBP) in two schools with high Aboriginal student populations in rural Western Australia, their contribution to holistic support, nutritional health education and possibilities for improvement. Method...
15 November 2019
In the vast majority of legislation on environmental noise, the metric used for expressing limit values is based on sound pressure levels. But some countries have introduced sound emergence limit values where the compliance of a noise-generating acti...
Dynamic stall is a critical limiting factor for airfoil aerodynamics and a challenging problem for active flow control. In this experimental study, dynamic stall was measured by high-frequency surface pressure tapes and pressure-sensitive paint (PSP)...
In the field of in situ measurement of high-temperature pressure, fiber-optic Fabry–Perot pressure sensors have been extensively studied and applied in recent years thanks to their compact size and excellent anti-interference and anti-shock cap...
This paper presents a study on design and development of an alternating pressure overlay consists of inflatable mini air bladders, which could be used in relieving and reducing tissue pressure for the treatment of pressure ulcers. Pressure ulcers, wh...
Population growth exacerbates the pressure on land carrying capacity, affecting the sustainability of agricultural production, and also impacts non-agricultural industries. This paper utilizes grain price data from southern China during the Qing Dyna...
Silicalite nanosheet (SN) laminated membranes are promising for pervaporation (PV) desalination of concentrated brines for water purification and critical material concentration and recovery. However, scaling up the SN-based membranes is limited by i...
We highlight here the fact that the distantly observed luminosity of a spherically symmetric compact star radiating thermal radiation isotropically is higher by a factor of (1+zb)2 compared to the corresponding flat space-time case, where zb is the s...
The present work aims to validate the computational simulation model that determines the static deflection experienced by rectangular flat plates along the longest edge when subjected to uniform and hydrostatic pressures, proposed as a state observer...
Noninvasive ventilation (NIV) during exercise has been suggested to sustain higher training intensity but the type of NIV interface, patient-ventilator asynchronies (PVA) or technological limitation of the ventilator may interfere with exercise. We a...
The study investigates the influence of atmospheric pressure fluctuations on methane emissions in a decommissioned coal mine in Poland (SRK S.A., KWK “Krupiński”). Continuous measurements of methane concentrations and atmospheric pre...
The instability of wellbore in hard and brittle shale formations is a key bottleneck constraining the safety and efficiency of drilling engineering. Traditional studies focused on drilling fluid density, particle plugging, and chemical inhibition; ho...
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