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Environmental Sciences

Numerical simulation

2022

Articles 1 - 8 of 8

Full-Text Articles in Engineering

Influence Of Thick Sandstone On Development Of Overburden Mining Fissures In Northern Shaanxi Coal Mining Area Of Yellow River Basin And Suggestions On Water-Preserved Coal Mining, Wang Shuangming, Wei Jiangbo, Song Shijie, Wang Shengquan, Sun Tao Dec 2022

Influence Of Thick Sandstone On Development Of Overburden Mining Fissures In Northern Shaanxi Coal Mining Area Of Yellow River Basin And Suggestions On Water-Preserved Coal Mining, Wang Shuangming, Wei Jiangbo, Song Shijie, Wang Shengquan, Sun Tao

Coal Geology & Exploration

The change of geological conditions of coal seam roof overburden and the development of mining fissures caused by coal mining activities are the direct causes of damage to the key underground aquifers, and also the root causes of ecological environment degradation in the mining area. As a typical geological condition, the thick sandstone developed in the overburden structure of the coal seam roof has an important impact on the development law of mining fissures in the overburden. Therefore, the influence of the thickness and location of different thick sandstones on the development morphology and height of overburden mining fractures was …


Occurrence Law Of Coal Seam Gas Under Influence Of Normal Fault Zone In Coal Measures, Xiao Peng, Wu Mingchuan, Shuang Haiqing, Han Kai, Gao Zhen, Cheng Yueying Oct 2022

Occurrence Law Of Coal Seam Gas Under Influence Of Normal Fault Zone In Coal Measures, Xiao Peng, Wu Mingchuan, Shuang Haiqing, Han Kai, Gao Zhen, Cheng Yueying

Coal Geology & Exploration

The coal measure fault zone generated by the superimposition of the polytropic movement and multiple structure has important effects on the coal seam gas occurrence. The method of combining the geologic analysis, COMSOL Multiphysics numerical simulation and field data monitoring was adopted to analyze the interaction relations between the stress distribution characteristics and faults of the normal fault zone in the coal measure, study the coal seam permeability variation characteristics influenced by the normal fault zone in the coal measure, and simulate the gas migration status and concentration distribution condition after the formation of the normal fault zone. The coal …


Numerical Simulation Of The Influence Of Karst Structure On Heat Transfer Efficiency Of Buried Pipeline Group, Mu Xuan, Pei Peng, Zhou Xin, Tu Hongsheng Oct 2022

Numerical Simulation Of The Influence Of Karst Structure On Heat Transfer Efficiency Of Buried Pipeline Group, Mu Xuan, Pei Peng, Zhou Xin, Tu Hongsheng

Coal Geology & Exploration

The buried pipeline is the part where the rock mass heat pump system performs direct heat transfer with the ground. The water-bearing structure in the karst area is complex and diverse, which has a significant impact on the heat transfer and storage of the buried pipeline group. Herein, the heat transfer process of a group of 27 vertical buried pipelines in four geological structure types was simulated, including the non-karst structure, fractured karst structure, karst conduit structure and mixed karst structure. Meanwhile, comparison was made for the change of parameters, such as the temperature field in the rock mass, the …


Study Of Advance Elaborate Detection With Transient Electromagnetic Method For Mine With Closed Poor Boreholes, Huang Zhongzheng, Jiang Guoqing, Wang Jun, Cheng Jiulong, Ma Zhi, Tian Chuxiao, Xin Chengtao Aug 2022

Study Of Advance Elaborate Detection With Transient Electromagnetic Method For Mine With Closed Poor Boreholes, Huang Zhongzheng, Jiang Guoqing, Wang Jun, Cheng Jiulong, Ma Zhi, Tian Chuxiao, Xin Chengtao

Coal Geology & Exploration

Closed poor boreholes connect aquifers at some degree to form well concealed water diversion channels, which poses a water hazard threat on either tunneling or working bench recovery. In order to discuss the effectiveness of using the transient electromagnetic method in the advance detection of closed poor boreholes for the mine, the 3D geologic-geophysical model of the closed poor boreholes in front of the tunneling working bench was established based on the full-space transient electromagnetic theory to simulate and study the response characteristics of the full-space transient electromagnetic field in the influence area model of closed poor boreholes. As indicated …


Abnormal Response Characteristic Simulation During Transient Electromagnetic Detection In Mine Borehole, Zhang Jun Aug 2022

Abnormal Response Characteristic Simulation During Transient Electromagnetic Detection In Mine Borehole, Zhang Jun

Coal Geology & Exploration

Conventional mine transient electromagnetic advance detection method is greatly influenced by the condition outside of the mine, which leads to the inaccurate location in anomalous body detection. In order to solve this problem, an advance detection method for measuring the three-component signals of the transient electromagnetic field in the down-hole borehole was proposed to carry out numerical simulation for the abnormal response characteristics from the different locations of the plane where the receiving coil is located and the different orientations of the anomalous body. The principle of borehole transient electromagnetic detection was analyzed, and the test design and construction design …


Failure Analysis Of Deep Coal Seam Floor Considering Strain Softening Of Surrounding Rock And Formation Contact In Goaf, Yin Shangxian, Meng Haopeng, Qian Shuangbin May 2022

Failure Analysis Of Deep Coal Seam Floor Considering Strain Softening Of Surrounding Rock And Formation Contact In Goaf, Yin Shangxian, Meng Haopeng, Qian Shuangbin

Coal Geology & Exploration

In order to study the failure mode of the floor in deep coal seam mining, we proposed a FLAC3D finite difference numerical method considering the strain softening of surrounding rock and the contact of goafs .Through the qualitative analysis of Rankine’s earth pressure theory, the failure of the deep coal seam floor is studied based on the measured water conducting fracture zone of the floor in working face 2023 of Linxi Mine. The results show that the mechanical state of surrounding rock after plastic failure can be described more accurately by using the strain-softening constitutive relationship instead of the …


Principle Of A Self-Protective Sealing Device For Mwd And Its Influencing Factors, Wang Yaoming, Ye Genfei, Zhao Yongzhe, Gao Ke, Liu Weiwei, Duan Huijun Apr 2022

Principle Of A Self-Protective Sealing Device For Mwd And Its Influencing Factors, Wang Yaoming, Ye Genfei, Zhao Yongzhe, Gao Ke, Liu Weiwei, Duan Huijun

Coal Geology & Exploration

For deeper drilling depth and longer service life of MWD, a self-protection sealing device for the MWD instrument is designed given the defects of the combined static sealing structure. The relationship between rubber airbag expansion displacement and air pressure was studied through static expansion numerical simulation. On this basis, the reasons for different results due to different model sizes were analyzed, and the factors causing the different simulation results of the self-protection sealing device were discussed. The four independent variables of airbag diameter, width, wall thickness and inner cavity width were determined and simulated to explore their relationship with the …


Characteristics Of Coal And Gas Outburst And Controlling Mechanism Of Stress Field In The Hanging Wall Of Normal Faults, Cao Yunxing, Zhang Haiyang, Zhang Zhen, Liu Gaofeng Apr 2022

Characteristics Of Coal And Gas Outburst And Controlling Mechanism Of Stress Field In The Hanging Wall Of Normal Faults, Cao Yunxing, Zhang Haiyang, Zhang Zhen, Liu Gaofeng

Coal Geology & Exploration

The fault zone is the main geological unit where coal and gas outbursts occur. Statistics of many coal and gas outbursts show that the number and intensity of the outbursts in the hanging wall are significantly greater than those in the foot wall for normal faults. However, there are few studies on the geological mechanism of this phenomenon, especially the variation of the in-situ stress field in the hanging wall of normal faults before and after mining, and its controlling mechanism of coal and gas outbursts that has not been completely demonstrated. In view of this, the normal fault DF …