scholarly journals Spatial and Temporal Distribution Law and Influencing Factors of the Mining-Induced Deformation and Failure of Gas Boreholes

2018 ◽  
Vol 2018 ◽  
pp. 1-15
Author(s):  
Fei Xue ◽  
Xiaowei Feng

Because gas boreholes are easy to damage by integrated coal mining and gas exploration, based on the practice of relieving pressure in deep thin coal seams in the Huainan mining area, a multidimensional coupling numerical simulation method was used to reveal the space-time evolution characteristics and influence factors of fracture deformation of gob-side gas boreholes. Results indicate that the danger zone for borehole fractures is primarily between 5 and 12 m above the roof of the roadway. The final-hole position has little effect on the stability of boreholes, and migrating the open-hole position to the entity coal side and roadway roof side can improve the stability of the borehole. The initial failure of the borehole occurs at a distance of 10 m behind the coal face. The failure of the borehole is largely stable at a distance of 100 to 120 m behind the coal face. With the increase in mining height, which leads to an increase in the movement of strata and an increase in pressure relief range, the shear stability of the borehole is reduced, and the extrusion stability of the borehole is improved. A hard roof condition promotes borehole shear stability, while a weak roof condition promotes borehole extrusion stability. This change can decrease the maintenance difficulty associated with “minor supports” in boreholes to a certain extent by reinforcing the support strength of “primary supports” in roadway retaining walls. The simulation results are consistent with observed results for the 11 test boreholes, and the accuracy of the numerical simulation is verified.

2018 ◽  
Vol 3 (12) ◽  
pp. 1189 ◽  
Author(s):  
Nian Zhang ◽  
Weihong Wang ◽  
Zhuoqiang Yang ◽  
Jianian Zhang

Horizontal rock strata is a geological condition of rock which is often encountered in the tunnel construction, and it has an important influence on the tunnel construction, it is necessary to analyze and study the stability of horizontal rock strata in tunnel construction to ensure the tunnel construction’s safety and efficiency. By taking “Xishan Highway Tunnel” as the research object, and using the numerical simulation method, the numerical model of the tunnel has been established in the Midas/GTS to simulate the tunnel excavation under the horizontal rock strata condition,and the deformation and failure mechanism of surrounding rock and the influence factors of surrounding rock stability after are studied and analyzed. The research focused on the displacement of surrounding rock horizontal and vertical deformation, the results show that the vertical displacement of the surrounding rock is obviously greater than that of other parts during the excavation of the horizontal rock tunnel. According to the calculation results, the optimization measures of horizontal stratum tunnel construction method are put forward, which has important reference value for ensuring the construction safety and construction quality.


2013 ◽  
Vol 353-356 ◽  
pp. 436-439
Author(s):  
De Sen Kong ◽  
Yong Po Chen

In order to forecast the stability of deep roadway and optimize the parameters of bolts, the complex stress environment and the multivariate surrounding rocks characteristics of deep roadway were analyzed. Then the classification prediction method and the numerical simulation method were simultaneously used to analysis the stability of surrounding rocks. Furthermore, the supporting parameters of bolts were also designed optimally. It was shown that the characteristics of stress distribution, deformation and failure zone of surrounding rocks are not ideal. So it is necessary to optimize the supporting parameters of deep roadway. All these research findings will provide the theory basis for bolts of deep roadway and will ensure the optimization of bolts and the stability of deep roadway in the long run.


2012 ◽  
Vol 535-537 ◽  
pp. 1542-1546
Author(s):  
Shun Li Fang ◽  
Shi Ping Jin ◽  
Yong Xiang Zhang ◽  
Su Yi Huang ◽  
Wu Qi Wen

The flow of the hydrogen has played an important role in the heat exchange in the inner bell. In this research, we have studied the volume distribution of the hydrogen in the inner bell through numerical simulation method, and we get the volume distribution law of the hydrogen when we change the axial angle and the tangential angle of the velocity of the hydrogen flowing into the inner bell while we do not change the speed of the hydrogen. This research could provide theory reference for the design and application of the structure of the coil base of the high performance hydrogen bell-type annealers later.


2013 ◽  
Vol 275-277 ◽  
pp. 1383-1388
Author(s):  
Cheng Liang Zhang ◽  
Lei Liu ◽  
Chun Wang

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.


2013 ◽  
Vol 663 ◽  
pp. 655-660
Author(s):  
Zhen Hua Xie ◽  
Zheng Lan Yuan ◽  
Yu Zhang

Aiming at the generation of blasting fume in underground blind roadway, numerical simulation method was taken to obtain the diffusion law of the blasting fume. In accordance with the actual situation in Shachang mining area of Shouyun iron mine, the physical model and mathematical model were set up, computational grids were divided, and the boundary condition was established. The diffusion law of blasting fume and the completion time under different explosives dosage were simulated by Fluent. The laws of blasting fume diffusion and diffusion time changing with the amount of explosive in local fan forced ventilation were obtained. The results can provide a theoretical basis for the research of a reasonable and effective ventilation manner of blind roadway.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Jun-hua Xue ◽  
Ke-liang Zhan ◽  
Xuan-hong Du ◽  
Qian Ma

In view of the damage of dynamic stress to the rock surrounding a mine roadway during coal mining, based on the actual geological conditions of Zhuji mine in Huainan, China, a UDEC model was established to study the influences of the thickness and strength of the direct roof above the coal seam and the anchorage effect on the stability of the roadway. The failure mechanism and effect of the dynamic stress on the rock surrounding a mine roadway were revealed. Under dynamic stress, cracks appear near the side of the roadway where the stress is concentrated. These cracks rapidly expand to the two sides of coal and rock mass. At the same time, the coal and rock mass at the top of the roadway fall, and finally, the two sides of coal and rock mass were broken and ejected into the roadway, causing a rock burst. However, when the same dynamic stress is applied to the roadway after supports are installed, there is no large-deformation failure in the roadway, which shows that, under certain conditions, rock bolting can improve the stability and seismic resistance of the surrounding coal and rock mass. Furthermore, by simulating the failure of surrounding rock with different strengths and thicknesses in the immediate roof, it is found that the thinner the roof, the greater the influence of the dynamic stress on the roadway; the stronger the roof is, the more likely the rock burst will occur with greater intensity under the same dynamic stress. A numerical simulation method was used to analyze the factors influencing rock bursting. The results provide a theoretical basis for research into the causes and prevention of rock bursts in deep mining areas.


2014 ◽  
Vol 638-640 ◽  
pp. 851-857
Author(s):  
Yi Luo ◽  
Xin Ping Li

The cracking and developing of structural surfaces is one of the main causes for surrounding rock mass large deformation and failure in deep underground cavern excavation. A numerical simulation method for discontinuous structural surface development is proposed based on the transient unloading of excavation load during underground cavern excavation. The program will automatically evaluate every substep in the dynamic calculation, and determine if the development stops and the cracking direction based on dynamic fracture mechanics. The penalty function is adopted to simulate the opening and sliding characteristic of structural surfaces. And the cracking path would be shown by iterative calculation. Results show that, the lateral pressure coefficient (LPC) is the main factor of cracking direction. When structural surface is shallow to the side wall, the crack would develop to the surface of the side wall. When it is deep enough into the side wall, the cracking might stop before it goes to the surface of the side wall. The accuracy of this simulation is verified by the comparison to relative laboratory tests.


2012 ◽  
Vol 616-618 ◽  
pp. 126-132 ◽  
Author(s):  
Hua Bin Wei ◽  
Shang Ming Shi ◽  
Pan Zhao ◽  
Dong Kai Huo ◽  
Wan Zhen Zhu

The high water cut stage on the residual oil distribution regularity in late development stage of oilfield is difficult in Daqing oilfield, North West Water Flooding fine demonstration zone development time is long, well under the complicated characteristic, adopts phase control of three-dimensional geological modeling and the method of reservoir numerical simulation in the demonstration zone, structural features and sedimentary characteristics of based on the establishment of demonstration zone, three-dimensional geological model. Through the application of fine reservoir numerical simulation method for the numerical simulation of remaining oil, and a summary of the demonstration zone of residual oil distribution law and cause of formation, provides reliable basis for the next step of oilfield development adjustment.


2019 ◽  
Vol 11 (10) ◽  
pp. 2758
Author(s):  
Gang Liu ◽  
Fengshan Ma ◽  
Haijun Zhao ◽  
Guang Li ◽  
Jiayuan Cao ◽  
...  

Cracks are critical for the deformation and failure of rock masses, but the effects of real cracks are rarely considered when evaluating the stability and safety of practical engineering. This paper presents a study on the application of fractures in the Sanshandao Gold Mine. Field investigation and statistical analysis methods were adopted to obtain the distribution laws of the cracks. Laboratory tests, MATLAB programming, and simulation using the software, GDEM (Gdem Technology, Beijing, China, Co., Ltd.), were employed to study the mechanical behaviors of rock masses with real fractures after excavation. The main results are as follows: (1) Three sets of highly discrete cracks were developed in the study area. Their inclination and dip can be approximately considered to follow a Gaussian distribution or uniform distribution. They had close ties to the three faults developed in the mining area. (2) Compared with the model that did not consider cracks and the model processed by the equivalence idea, the surrounding rock deformation caused by excavation of the model that considered real cracks was larger than that of the former and smaller than that of the latter. However, its influence range was larger than that of the other two models. The results show that it is reasonable to use three sets of discrete cracks to characterize the fracture distribution of the surrounding rock. In the evaluation of roadway stability, it is not advisable to use the equivalence method to deal with all the cracks. Considering a part of the cracks that are compatible with the size of the calculation model, a relatively accurate evaluation can be obtained in terms of the deformation, failure, and permeability changes of the surrounding rock.


2011 ◽  
Vol 361-363 ◽  
pp. 166-170 ◽  
Author(s):  
Jun Ling Hou

In background of the geological engineering and the mining technical conditions of ZhangJi coal mine 17258 fully-mechanized face and rail roadway of 1724 (1) fully-mechanized face,by the field observation and computer numerical simulation studying the stress distribution law of roadway surrounding rock heading advancing coal face.Obtain the influence scope of the dynamic pressure along coal seam trend and tendency, the stress peaks position, perturbation boundary angle of dynamic pressure,and the surrounding rock stress distribution law of roadway excavating in the zone of the stress concentration and stress reduced area. Provides the theoretical foundation for roadway layout under similar conditions.


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