scholarly journals Numerical simulation of the effect of fault inclination on the sudden water of the fault bottom plate

2020 ◽  
Vol 185 ◽  
pp. 02026
Author(s):  
Xiao-Liang Jia
Keyword(s):  
Base Plate ◽  
Mining Area ◽  
Simulation Software ◽  
Bottom Plate ◽  
Working Surface ◽  
Safety Design ◽  
Pressure Water ◽  
Ground Stress ◽  
Small Inclination ◽  
Surface Plate

The main reason for the frequent occurrence of water accidents on the bottom plate of the working surface near the mine fault in China is that the excavation activities cause the fault to activate and direct the pressure water of the aquifer. The distribution of ground stress fields and plastic regions under the influence of extraction disturbance spree is analyzed by using the flaC3D simulation software FLAC3D simulation software. The results show that the greater the inclination of the fault, the greater the shear stress and the normal stress at the fault level, and the deeper the activation range of the mining fault is larger than that of the shallow one ,and the small inclination positive fault is more likely to produce the fissure between the working surface base plate and the aquifer, and the small inclination positive fault should be left with a wider water-bearing coal column in the actual safety design. Using this software, the evolution of the stress field and plastic zone in the adjacent mining area is a preview, which is of great application value to prevent the surface plate burst water and determine the retention width of the fault waterproof coal column.

Case Study on Modeling Fire Action Complexity in Fire Safety Engineering of Structures

2017 ◽  
Vol 21 ◽  
pp. 102-107
Author(s):  
Constantin Sorin Scutarasu ◽  
Dan Diaconu-Şotropa ◽  
Marinela Barbuta
Keyword(s):  
Numerical Simulation ◽  
Fire Safety ◽  
Simulation Software ◽  
Dynamics Simulation ◽  
Structural Safety ◽  
Modular Organization ◽  
Field Of Study ◽  
Safety Design ◽  
Fire Safety Design ◽  
Technical Regulations

Important goals in the fire safety design, such as preventing loss of life and goods damage, are achieved by maintaining the stability of structures exposed to fire for a period of time established by norms and standards. Real fire scenarios confirm that the specific technical regulations which actually have a prescriptive character (both national and international) do not deal with sufficient possibilities regarding the assessment of structural fire safety. The new approach on structural safety, based on engineering notions, gives us additional prospects on it and it is included in the issues of the fire safety design of structures. A relatively new field of study, known by a few professionals focused on fire safety (but well acknowledged in the research area), fire safety design met with lots of changes and restructuring of the governing concepts and procedures and of the information with which they operate, due to the fast accumulation of experience in this area of engineering activity. Consequently, after countries such as Australia, Canada, New Zeeland or USA provided towards professionals specific technical regulations for fire safety design, groups of experts in these aforementioned countries have joined their forces to try to diminish the differences that exists between those regulations and to give a unitary character to them, a better conceptualized engineering approach of the fire safety design. The result: occurrence of the publication International Fire Engineering Guidelines (last edition from 2005). The systematic approach of fire safety design in constructions pointed, once again, the possibility of modular organization of this field of study, the relations between modules being established according to the objective or objectives in the fire safety design for a specified building. This article aims to put forward, from this modularized perspective, the study of the fire safety design of a building exposed to fire; hence, the practical part of the article exhibits the numerical simulation of initialization and development of the fire process for a large scale religious building. The main features of the building represent the amount of space that facilitates the spreading of smoke and warm gases and which increases the risk of damaging the structural reinforced concrete elements. Application calls to specific numerical simulation with a higher degree of credibility, such as those realized by the FDS (Fire Dynamics Simulation) software.

scholarly journals High-density bimodal bentonite blends for hydraulic sealings at the Ibbenbüren coalmine

Clay Minerals ◽  
2015 ◽  
Vol 50 (3) ◽  
pp. 391-403 ◽  
Author(s):  
Felicitas Wolters ◽  
Wiebke Baille ◽  
Katja Emmerich ◽  
Eva Schmidt ◽  
Christian Wolters ◽  
...  
Keyword(s):  
Swelling Pressure ◽  
Mining Area ◽  
Applied Strain ◽  
Sand Mixture ◽  
Pressure Tests ◽  
Pressure Development ◽  
Pressure Water ◽  
Sufficient Magnitude ◽  
Sealing Materials ◽  
Oedometer Tests

AbstractThe two high-pressure water-retaining dams at the Ibbenbüren coalmine in Münsterland (Germany) have to perform reliably under the induced tension caused by further exploitation of the current mining area. The load-bearing and the sealing functions of the new barriers were separated and new sealing materials were developed. An innovative multilayer sealing system of bentonite and sandwiched equipotential layers (SANDWICH) supporting homogeneous swelling and sealing, independent of formation water (Nüesch et al., 2002), was applied in this project. A testing program of strain-controlled swelling pressure tests on compacted bentonite specimens and on a bentonite/sand mixture was conducted to ensure an adequate potential for swelling-pressure development.The measurements under constant volume for dry densities between 1.45 g/cm3 and 1.67 g/cm3 showed an evolving swelling pressure between 1.04 and 1.8 MPa for 100% bentonite samples. Straincontrolled oedometer tests for zero strain and step-wise applied strain up to 2% revealed that a sufficient magnitude of swelling pressure existed at maximum applied strain.

Numerical Simulation Research of Optimization Design of Supporting Half-Coal Roadway in Deep Stope Working Face

2014 ◽  
Vol 945-949 ◽  
pp. 1169-1174
Author(s):  
Xian Tao Zeng ◽  
Ning Wang ◽  
Cong Jiang ◽  
Yun Yi Zhang ◽  
Chang Hai He
Keyword(s):  
Numerical Simulation ◽  
Optimization Design ◽  
Mining Area ◽  
Support Design ◽  
Simulation Research ◽  
Actual Measurement ◽  
Design Scheme ◽  
Coal Roadway ◽  
Working Face ◽  
Ground Stress

In this paper, design of roadway with stope working face Yeqing 8459 had been optimized combined with geological characteristics of the working face based on the actual measurement of ground stress and mechanical properties of coal rock of Yangquhe mine in Feng Feng mining area. Analyzing eight kinds of roadway support design scheme through numerical simulation and evaluating the supporting effect of each supporting design scheme, designating the construction guidelines ultimately.

scholarly journals Onsite Tests and Numerical Simulation of Broken Rock Zones in Surrounding Rocks of Seepage Roadways under Blasting

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Zhouyuan Ye ◽  
Kun Pan ◽  
Zhihua Zhou
Keyword(s):  
Numerical Simulation ◽  
Shear Failure ◽  
Mechanical Response ◽  
Water Pressure ◽  
Mining Area ◽  
Seepage Water ◽  
Blasting Vibration ◽  
Fracture Density ◽  
Iron Mine ◽  
Ground Stress

To study the influence of blasting vibration on the broken rock zone around a seepage roadway and provide guidance for design of the roadway support, the broken rock zones around rock of seepage roadways under production blasting vibration are determined by onsite tests in a mining area, Daye iron mine. During the testing process, it is found that blasting vibration causes internal cracks of surrounding rocks to initiate and develop, the fracture density increases, the acoustic wave velocity of rock mass decreases, and the broken rock zones expand. At the same time, through onsite observation, it is found that blasting vibration results in crack development and formation of a water pathway to lead to surface water into the ground. The mechanical response around rock of the seepage roadway under blasting vibration is simulated by the two-dimensional realistic fracture progress analysis calculation software (RFPA2D). It is found that internal cracks of roadway surrounding rock initiate, propagate, and join up gradually, and the fracture range is expanding under the seepage water pressure, ground stress, and cyclic loads, and the broken rock zones also expand. The results from numerical simulation are consistent with the results of onsite tests. It is also found that the tensile stress appears around some cracks, leading to part of the cracks more likely to generate shear failure under the seepage water pressure during simulation.

Apply Roof-Broken the Blasting Technique to Control Rock Burst

2014 ◽  
Vol 522-524 ◽  
pp. 1377-1381
Author(s):  
Zhen Wen Liu ◽  
Chuan Bo Hao
Keyword(s):  
Rock Burst ◽  
Mining Area ◽  
Shock Pressure ◽  
Effective Control ◽  
Design Parameters ◽  
Successful Implementation ◽  
Actual Situation ◽  
Working Surface ◽  
Power Mutation ◽  
Mining Work

In working mining process of No.108 coal seam in Shengli Mine, the lower triangular goaf area hanging arch caused shock pressure. For this, The theoretical analysis do this weaken the roof through the roof-broken blasting technology, to optimize blasting design parameters, combined with the actual situation of the working surface to improve the blasting process, improve the top relief solve risk technology and solve the problem of rock burst. The application shows: successful implementation of advanced deep hole pre-splitting blasting to address a key challenge for charge and blasting technology, effective control of the roof power mutation occurs, improve the safety factor of the mining area, and provides an important mining work under similar conditions.

Analysis of the stress-strain state in carburized gearwheels

2021 ◽  
pp. 13-20
Author(s):  
N. I. Kitaev ◽  
S. Ya. Pichkhidze
Keyword(s):  
3D Model ◽  
Gear Wheel ◽  
Static Strength ◽  
Simulation Software ◽  
Chemical Heat Treatment ◽  
Structural Alloy ◽  
Chemical Heat ◽  
Working Surface ◽  
Before And After ◽  
Static Fracture

This article studies the static strength, static fracture and stiffness of the teeth of a wheel made of structural alloy steel of 12KhN3А grade before and after the carburizing of the working surface. The results of the analysis show that the static strength and static destruction of the part before and after chemical heat treatment are approximately equal, however, the gear wheel, strengthened by this method, has a higher hardness. The study and simulation of the applied loads were carried out using a 3D-model in the SolidWorks 2018 Simulation software.

scholarly journals Thermal Effect on a CIGS Thin-Film Solar Cell P2 Layer by Using a UV Laser

2014 ◽  
Vol 6 ◽  
pp. 723136 ◽  
Author(s):  
Dyi-Cheng Chen ◽  
Ming-Fei Chen ◽  
Ming-Ren Chen
Keyword(s):  
Stainless Steel ◽  
Solar Cell ◽  
Simulation Analysis ◽  
Processing System ◽  
Base Plate ◽  
Simulation Software ◽  
Experimental Results ◽  
Uv Laser ◽  
Cigs Solar Cell ◽  
Laser Apparatus

This study used ANSYS simulation software for analyzing an ultraviolet (UV) (355 nm) laser processing system. The laser apparatus was used in a stainless steel CIGS solar cell P2 layer for simulation analysis. CIGS films process order according to S iO2 layer, molybdenum electrode, CIGS absorbed layer, CdS buffered layer, i-ZnO penetrate light layer, TCO front electrode, MgF resist reflected materials, andelectrode materials. The simulation and experimental results were compared to obtain a laser-delineated P2 laser with a low melting and vaporization temperature. According to the simulation results, the laser function time was 135 μs, the UV laser was 0.5 W, and the P2 layer thin films were removed. The experimental results indicated that the electrode pattern of the experiment was similar to that of the simulation result, and the laser process did not damage the base plate. The analysis results confirm that the laser apparatus is effective when applied to a stainless steel CIGS solar cell P2 layer.

scholarly journals Customising Evacuation Instructions for High-Rise Residential Occupants to Expedite Fire Egress: Results from Agent-Based Simulation

Fire ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 21
Author(s):  
Michael Gerges ◽  
Peter Demian ◽  
Zulfikar Adamu
Keyword(s):  
Fire Safety ◽  
Residential Buildings ◽  
Residential Building ◽  
Simulation Software ◽  
Evacuation Time ◽  
Agent Based ◽  
High Rise ◽  
Safety Design ◽  
Fire Safety Design ◽  
Simulation Results

As the possibility of safe escape is one of the most crucial aspects of a building’s fire safety features, understanding of human behaviour under fire conditions is important for a successful evacuation. Although most of today’s buildings are equipped with fire safety systems, a fire can still occur at anytime and anywhere in a building and have devastating consequences. In the last decade, researchers and practitioners have used information technology to assist with fire safety design and emergency management. Building Information Modelling (BIM) is an exemplar process whose underpinning digital technology has been helpful for fire safety design, simulation, and analysis, but there is a lack of research on how BIM-based models combined with agent-based simulations can help improve evacuation via effective navigation and wayfinding in high-rise residential buildings. Customising evacuation instructions based on BIM, simulation results and occupant location, and delivery of these bespoke instructions to occupants’ smartphones during a fire emergency is relatively novel and research is needed to realise the potential of this approach. Therefore, this study investigates how customised evacuation instructions delivered to each occupant in a high-rise residential building could result in a faster evacuation during a fire incident. The research adopted a case study building and used Pathfinder (agent-based evacuation simulation software) to simulate evacuation from this eleven-floor high-rise residential building in Cairo, Egypt. Constraining evacuees (simulated agents in Pathfinder) to take particular exit routes was used as a proxy for delivering customised evacuation instructions to actual evacuees. Simulation results show that, in general, allowing the use of lifts for the benefit of disabled occupants could lead to their misuse by able-bodied occupants; evacuees would attempt to use the first visible point of exit regardless of how crowded it is. With optimally customised instructions, the evacuation time was, on average, 17.6 min (almost 50%) shorter than when the occupant’s choice of egress route was simulated based on standard path planning factors such as route length, nearby crowds and visible hazards. With evacuation instructions sent via smartphones, occupants could exit more rapidly via alternative routes. Such bespoke instructions were shown to reduce the adverse effects of crowdedness and uneven distribution of occupants along vertical and horizontal evacuation routes on evacuation time.

scholarly journals Analysis of Mechanical Characteristics and Instability Law of Inverse Fault under the Influence of Mining

2018 ◽  
Vol 22 (2) ◽  
pp. 139-144
Author(s):  
Yuanhui Li ◽  
Rui Zhou
Keyword(s):  
Fault Zone ◽  
Mechanical Characteristics ◽  
Simulation Software ◽  
Shear Stresses ◽  
Reverse Fault ◽  
Working Surface ◽  
Working Face ◽  
Changing Trend ◽  
Distance Conditions ◽  
Normal And Shear Stresses

In order to explore the mechanical characteristics and stability of the reverse fault under the influence of mining, an inverse mechanics model has been built under work face mining conditions, according to the law of working surface pressure distribution. As a result, a theoretical calculation equation of the normal and shear stresses in the fault zone have been deduced to obtain the stress variation rule between the working surface and the fault layer, under distance conditions of 10, 30, 50, and 70m. With distance conditions of 10 and 30m, the working surface mining stress had an obvious effect on the reverse fault, resulting in a changing trend of firstly increasing, then decreasing, and increasing again in the normal and shear stresses of the fault zone as a whole. With distance conditions of 50 and 70m, the working face mining stress had little effect on the reverse fault; furthermore, the normal and shear stresses exhibited a changing trend of gradually increasing. At a later stage, a simulation of the above distance plans was conducted using the FLAC3D numerical simulation software. The results demonstrated that the influence range of the mining stress on the working face under the spacing distances of 10 and 30m included the fault zone, while under the distance conditions of 50 and 70m, the fault zone was excluded. On this basis, the fault zone stability was analysed under four types of spacing conditions by means of the Mohr Coulomb theory rule and fault activation determination. It is concluded that the fault zone stability was high, with increasing distances between the working face and fault zone. The least sufficient stability was located near the working face, where the fault zone stability was so poor that it is likely to result in impact fracture.

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