scholarly journals Numerical Simulation of Geostress and Support of Roadway Crossing Strata in Complex Stress Condition

2012 ◽  
Vol 446-449 ◽  
pp. 1781-1784
Author(s):  
Tong Xu Wang ◽  
Lai Yuan Li ◽  
Wen Hai Zheng ◽  
Yang Liu ◽  
Tao Hou ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Mining Area ◽  
Complex Stress ◽  
Simulation Software ◽  
Stress Variation ◽  
Roof Structure ◽  
Rock Structure ◽  
Stability Classification ◽  
The Stability ◽  
The Impact

Affected by a group of underground chambers and gobs of working faces, the track sub-inclined shaft of 430 mining area in Geting coal mine, which crosses coal seam and faults repetitively, lies in high and complex stress environment. Based on geostress results measured in the field, FLAC3D numerical simulation software was used to simulate the regional geostress in the area near the roadway, referring to the impact of the gobs and chambers. And the stress variation law along the roadway was given at last. Then the roadway roof structure zone chart was drawn according to the detection results with the rock video detection recorder. Finally, stability of different sections of the roadway and the support advice corresponding to each section was gained. The results show that comprehensive consideration of geostress variation law and surrounding rock structure is necessary in the stability classification and the support of roadways. The research methods and ideas given in this paper is feasible.

scholarly journals Surrounding Rock Movement of Steeply Dipping Coal Seam Using Backfill Mining

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Wenyu Lv ◽  
Kai Guo ◽  
Jianhao Yu ◽  
Xufeng Du ◽  
Kun Feng
Keyword(s):  
Numerical Simulation ◽  
Coal Seam ◽  
Surrounding Rock ◽  
Maximum Deflection ◽  
Coal Seams ◽  
Physical Similarity ◽  
Working Face ◽  
Rock Structure ◽  
Backfill Mining ◽  
The Stability

The movement of the overlying strata in steeply dipping coal seams is complex, and the deformation of roof rock beam is obvious. In general, the backfill mining method can improve the stability of the surrounding rock effectively. In this study, the 645 working face of the tested mine is used as a prototype to establish the mechanical model of the inclined roof beam using the sloping flexible shield support backfilling method in a steeply dipping coal seam, and the deflection equation is derived to obtain the roof damage structure and the maximum deflection position of the roof beam. Finally, numerical simulation and physical similarity simulation experiments are carried out to study the stability of the surrounding rock structure under backfilling mining in steeply dipping coal seams. The results show the following: (1) With the support of the gangue filling body, the inclined roof beam has smaller roof subsidence, and the maximum deflection position moves to the upper part of working face. (2) With the increase of the stope height, the stress and displacement field of the surrounding rock using the backfilling method show an asymmetrical distribution, the movement, deformation, and failure increase slowly, and the increase of the strain is relatively stable. Compared with the caving method, the range and degree of the surrounding rock disturbed by the mining stress are lower. The results of numerical simulation and physical similarity simulation experiment are generally consistent with the theoretically derived results. Overall, this study can provide theoretical basis for the safe and efficient production of steeply dipping coal seams.

Analysis of drivers' characteristics in car-following theory

2014 ◽  
Vol 28 (24) ◽  
pp. 1450191 ◽  
Author(s):  
Geng Zhang ◽  
Di-Hua Sun ◽  
Hui Liu ◽  
Min Zhao
Keyword(s):  
Numerical Simulation ◽  
Traffic Flow ◽  
Mkdv Equation ◽  
Reductive Perturbation Method ◽  
Linear Stability Theory ◽  
Traffic Density ◽  
Car Following ◽  
Car Following Model ◽  
The Stability ◽  
The Impact

In recent years, the influence of drivers' behaviors on traffic flow has attracted considerable attention according to Transportation Cyber Physical Systems. In this paper, an extended car-following model is presented by considering drivers' timid or aggressive characteristics. The impact of drivers' timid or aggressive characteristics on the stability of traffic flow has been analyzed through linear stability theory and nonlinear reductive perturbation method. Numerical simulation shows that the propagating behavior of traffic density waves near the critical point can be described by the kink–antikink soliton of the mKdV equation. The good agreement between the numerical simulation and the analytical results shows that drivers' characteristics play an important role in traffic jamming transition.

Stability Analysis of Side Slope under Normal and Rainfall Conditions

2013 ◽  
Vol 275-277 ◽  
pp. 1383-1388
Author(s):  
Cheng Liang Zhang ◽  
Lei Liu ◽  
Chun Wang
Keyword(s):  
Numerical Simulation ◽  
Simulation Method ◽  
Unstable State ◽  
Electrical Method ◽  
Rainfall Condition ◽  
Long Term Stability ◽  
Side Slope ◽  
Numerical Simulation Method ◽  
The Stability ◽  
The Impact

The paper studied a side slope engineering of highway in K29+450~K29+900 sections by making an on-site survey of landform and geological features of the side slope. By combining drilling, high-density electrical method and numerical simulation method, the depth and range of the sliding surface were determined. The stability of the side slope after an excavation in a normal and a rainfall conditions was analyzed using numerical simulation method, and simulation results show that in the normal condition the safety factor of the side slope is 1.12, and it is 1.05 in the rainfall condition; the distribution of plastic zones is wide, especially in the rainfall condition, the side slope has a large deformation and is in an unstable state. When a program of side slope reinforcement is chosen, the impact under rainfall condition should be considered in order to ensure long-term stability of side slope.

Research on Cataclastic Rock Bolting Control

2015 ◽  
Vol 730 ◽  
pp. 117-121
Author(s):  
Pei Xin Dong ◽  
Zhi Qiang Yang ◽  
Qian Gao ◽  
Hai Zhi Ma ◽  
Xiao Guang Wu ◽  
...  
Keyword(s):  
Mining Area ◽  
Difficult Problem ◽  
Engineering Properties ◽  
Deformation Characteristics ◽  
Joint Development ◽  
Rock Bolting ◽  
Rock Structure ◽  
Cataclastic Rock ◽  
Supporting Effect ◽  
The Stability

Due to the complexity of cataclastic rock structure, joint development, cataclastic rock bolting is a difficult problem to solve. According to roadway engineering properties and deformation characteristics of liu qiao one ore two level six mining area-380 transport cross section, choose one supporting form, adopt the method of numerical simulation to analysis its supporting effect, to ensure the stability of surrounding rock and the safe running of the roadway.

scholarly journals Control of Gob-Side Roadway with Large Mining Height in Inclined Thick Coal Seam: A Case Study

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Xie Fuxing
Keyword(s):  
Numerical Simulation ◽  
Coal Pillar ◽  
Simulation Software ◽  
Surrounding Rock ◽  
Mine Pressure ◽  
Thick Coal Seam ◽  
Working Face ◽  
Rock Structure ◽  
Large Mining Height ◽  
Mining Height

The gob-side roadway of 130205, a large-mining-height working face in the Yangchangwan coal mine, was investigated in terms of the mine pressure law and support technology for large mining heights and narrow coal pillars for mining roadways. The research included field investigations, theoretical analysis, numerical simulation, field tests, and other methods. This paper analyzes the form of movement for overlying rock structure in a gob-side entry with a large mining height and summarizes the stress state and deformation failure characteristics of the surrounding rock. The failure mechanism of the surrounding rock of the gob-side roadway and controllable engineering factors causing deformation were analyzed. FLAC3D numerical simulation software was used to explore the influence law of coal pillar width, working face mining height, and mining intensity on the stability of the surrounding rock of the gob-side roadway. Ensuring the integrity of the coal pillar, improving the coordination of the system, and using asymmetric support structures as the core support concept are proposed. A reasonably designed support scheme for the gob-side roadway of the working face for 130205 was conducted, and a desirable engineering effect was obtained through field practice verification.

scholarly journals Vertical Shaft Support Improvement Studies by Strata Grouting at Aquifer Zone

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Qing Yu ◽  
Kexin Yin ◽  
Jinrong Ma ◽  
Hideki Shimada
Keyword(s):  
Compressive Force ◽  
Injection Pressure ◽  
Negative Influence ◽  
New Method ◽  
Stress Variation ◽  
High Injection Pressure ◽  
Shaft Lining ◽  
The Stability ◽  
The Impact ◽  
Chain Conveyor

The shaft lining failure which occurs in deep alluvium is a sudden coal mine hazard. The strata grouting is one of the treatment methods for the shaft lining failure. To investigate the impact of grout injection pressure on the shaft lining, the field measurement and the numerical analysis of the shaft lining stress variation during the grouting were conducted. To improve the strata grouting, the underground continuous impervious curtain (UCIC) is proposed as a new method by using the chain conveyor cutter technique without the impact on the shaft lining. The effects of the new method were also analyzed by means of the numerical methods. The results show that the strata grouting in the deep alluvium needs a high injection pressure, and in the horizontal direction, the shaft lining sustains the repeat tensile and compressive force during the grouting process. The negative influence of strata grouting on the stability of the shaft lining is obvious and serious. The UCIC built around the shaft lining can restrain the stress concentration induced by the aquifer drawdown. The triangular UCIC has a similar effect as that of the vertical one, and the small angle is better for preventing the shaft lining failure.

Research on the Overlying Strata in Full-Mechanized Coal Mining of Datong Jurassic Coal Multi-Layer Goaf

2012 ◽  
Vol 616-618 ◽  
pp. 402-405 ◽  
Author(s):  
Hong Chun Xia ◽  
Guo Sheng Gao ◽  
Bin Yu
Keyword(s):  
Coal Seam ◽  
Coal Mining ◽  
Coal Pillar ◽  
Mining Area ◽  
Mechanics Model ◽  
Roof Structure ◽  
Geological Conditions ◽  
Seam Mining ◽  
The Impact ◽  
Overlying Strata

According to the specific geological conditions in themulti-layer worked-out areas of Yongding coal seam, by the methods of integration of theoretic analysis, numerical value calculation and so on, we studied movement law of Overlaying Strata and influence of coal pillar in Coal seam mining, obtained the basic law of the overlying strata movement in multiplayer, provides a theoretical basis for the safe and efficient exploitation of the success of multiplayer. Many mining area in China is mining of closed distance coal seam group, By the impact of coal seam in the overlying, face and the tunnel roof structure will be different injury in sub-coal seam mining, Roof structure has changed greatly, even damage and easily take the roof leakage, When the the goaf communication with the overlying coal seams, caused by the induced secondary disasters such as face air leakage, Therefore, exploitation of the law of motion of the overlying strata in the multiplayer is a pressing problem. Exploitation multiplayer seam few theoretical and technical foundation at home and abroad, affecting the validity of the mining, rationality. although a lot of research on theory and technology of coal mining over the years[1~5], But it was not able to an overall comprehensive analysis of upper goaf adjacent goaf and overlying the coal pillar and present mining face, create a dynamic structural mechanics model, which is likely to cause the occurrence of disasters.

Numerical Studies on Low-Velocity Impact Failure Response of Al 1100 under Blunt and Hemispherical Impactors

2018 ◽  
Vol 917 ◽  
pp. 218-222 ◽  
Author(s):  
Sonika Sahu ◽  
Mohd Zahid Ansari ◽  
Chong Du Cho
Keyword(s):  
Numerical Simulation ◽  
Impact Analysis ◽  
Failure Modes ◽  
Simulation Software ◽  
Low Velocity Impact ◽  
Impact Behavior ◽  
Nose Radius ◽  
Low Velocity ◽  
Velocity Impact ◽  
The Impact

Numerical simulation is performed to study the deformation and failure modes of Al 1100 plate of 2.4 mm thickness, subjected to low-velocity impact. Blunt and hemispherical nose shaped impactors are used in this study. The quasi-static tensile test is performed at a strain rate of 0.01/s to obtain the Johnson-Cook material parameters which are used in numerical simulation software, ABAQUS/CAE to perform impact analysis. Mesh convergence study is carried out to decide the appropriate number of elements for numerical analysis. The impact behavior of Al 1100 plate for each impactor shapes are studied at 22 J impact energy. Result indicate that increased in the nose radius of impactor will increase the amount of deformation energy for aluminium plate.

Study on the Influence of Ice-Water Coupling on Numerical Calculation of Ice Load

2018 ◽  
Author(s):  
Hui Li ◽  
Zheng Yang ◽  
Yan Feng ◽  
Yu-Bo Wang ◽  
Si-Yu Wang
Keyword(s):  
Numerical Simulation ◽  
Numerical Calculation ◽  
Sea Ice ◽  
Sea Water ◽  
Coupling Effect ◽  
Simulation Software ◽  
Ice Load ◽  
Local Strength ◽  
Ice Water ◽  
The Impact

The interaction between sea ice and sea water is a complicated fluid-solid coupling dynamic process during the operation of polar ships. Using the finite element numerical simulation software LS-DYNA to simulate the continuous ice breaking of icebreaker, the ice load numerical calculation method considering the ice water coupling is presented. The effect of ice water coupling on ice load is studied. Based on the ice pool test data and the calculated results of this paper, the accuracy and rationality of the algorithm are verified. On this basis, the multiple factors affecting the coupling between sea ice and sea water are further studied, including the thickness of sea ice and the collision velocity of ship and ice which are affected by the environment of different polar sea areas. By simulating the numerical results obtained from the collision ice breaking of the targeted ship, the influence of various factors on the coupling effect between sea ice and sea water is summarized, and the local strength of the hull head structure is checked and evaluated. Furthermore, the impact-type icebreaking ability of the hull is put forward, which has certain guiding significance for the development of ship ice collision numerical simulation.

Stability Analysis of Tunnel during the Excavation Based on ANSYS

2014 ◽  
Vol 577 ◽  
pp. 1135-1138
Author(s):  
Bing He ◽  
Guang Zhi Yin
Keyword(s):  
Numerical Simulation ◽  
Stability Analysis ◽  
Stress Condition ◽  
Stability Control ◽  
Simulation Software ◽  
Surrounding Rock ◽  
Geological Condition ◽  
Rock Stability ◽  
Before And After ◽  
The Stability

This paper combines the geological condition of Miaoziwan tunnel and numerical simulation software ANSYS to analyze the displacement and stress condition of surrounding rock before and after the excavation. Furthermore, the stability of overlying rock in the tunnel was studied based on the displacement and stress condition of surrounding rock. The breaking law of overlying rock was studied considering the influencing factors to the stability of surrounding. The study and analysis to the breaking law of overlying rock can be helpful to the improvement of surrounding rock stability control and supporting system. Moreover, the result can be the guidance to the excavation.

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