Discrimination and application of the properties of the in-seam seismic wave in the collapse column of the working face

There are many karst collapse columns in coal seam roof in the southern coal field in China, which are different from those in coal seam floor in the northern coal field, due to the stratum characteristics. The karst collapse column in coal seam roof tends to reactivate and conduct water and induce the serious water inrush disaster, when the karst collapse column communicates with the overlying aquifer. In order to reveal the evolution mechanism of water-conducting channel of collapse column in karst mining area of southwest China, the aquifers and water inflow rule in 1908 working face in Qianjin coal mine are analyzed. Besides, the particle size distribution and mineral component of collapse column are researched by the X-ray diffraction test and the screening method, which are the basis for researching the water inrush mechanism in karst collapse column. On this basis, the water inrush of roof collapse column under the influence of mining is researched by establishing the numerical calculation model with the UDEC numerical software. The results show that the water flowing into the 1908 working face comes from the Changxing formation aquifer and Yulongshan formation aquifer above the coal seam, and the proportion of coarse particles and fine particles in collapse column is 89.86% and 10.14%, respectively. With the advance of working face, the water-conducting channel connected the working face with the aquifer, or the surface is formed by collapse pits, karst caves, and collapse column. The research results can be treated as an important basis for the water-preserved mining in southern coal field in China.

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Evaluation on water bursting risk of working faces near collapse column during the mining process

E3S Web of Conferences ◽

10.1051/e3sconf/202019802003 ◽

2020 ◽

Vol 198 ◽

pp. 02003

Author(s):

Yang Xue ◽

Huang Jingwu ◽

Wang Hua ◽

Liang Maoliang ◽

Li Wei ◽

...

Keyword(s):

Coal Seam ◽

Fracture Zone ◽

Economic Loss ◽

Mining Area ◽

Mining District ◽

Maximum Height ◽

The West ◽

Working Face ◽

Collapse Column ◽

Water Bursting

Collapse column water bursting occurs from time to time in the coal mining process of North China Type Coalfield in China, which causes great economic loss and personal injury. Therefore, great attention must be paid to the harm of collapse column. 1301 working face and 1306 working face in the west wing of No.1 Mining District of Zhangji Coal Mine in Shanxian County are close to No.2 collapse column. Water bursting risk evaluation must be carried out before mining two working faces to ensure safety production. On the basis of fully analyzing the geological and hydrogeological conditions of the 3up coal seam in the west wing of No.1 Mining Area, the "Three Zones(caving zone, water conducted fracture zone and sagging zone) Theory of Coal Seam Roof", "Strata Movement Theory" and "Water Bursting Coefficient Theory" were used respectively to calculate and evaluate the water bursting risk of No.2 collapse column during the course of mining the 1301 working face and 1306 working face. The results show that: firstly, in the process of mining the 1301 working face, the maximum height of the water conducted fracture zone at the closest position of 1301 working face to No.2 collapse column would be 60.20 m, the water bursting coefficient on the boundary of water conducted fracture zone would be 0.066~0.072 MPa/m, and the water bursting risk of the No.2 collapse column would be smaller; secondly, in the process of mining the 1306 working face, the maximum height of the water conducted fracture zone at the closest position of 1306 working face to No.2 collapse column would be 60.91 m, the water bursting coefficient on the boundary of water conducted fracture zone would be 0.057~0.089 MPa/m, and the water burst risk of the No.2 collapse column would be small. By August 31, 2020, the 1301 working face had been safely mined more than 200 meters long(exceeding over 120 m of the closest position in 1301 working face to No.2 collapse column), and the water bursting did not happen in the working face. This paper can provide a reference for the water prevention and control of similar collapse columns in coal mines.

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Research on Characteristic Recognition and Dangerous Prevention While Mining through Collapse Column of Pansan Minefield,China

10.21203/rs.3.rs-779433/v1 ◽

2021 ◽

Author(s):

Haitao Xu ◽

hui yang ◽

Wenbin Sun ◽

Lingjun Kong ◽

Peng Zhang

Keyword(s):

Coal Seam ◽

Water Inrush ◽

Coal Pillar ◽

Simulation Software ◽

Coal Seams ◽

Transient Electromagnetic ◽

Working Face ◽

Electromagnetic Detection ◽

Floor Failure ◽

Collapse Column

Abstract In order to find out the characteristics of geological isomer exposed in the mining process of 12318 working face in Pansan Mine and grasp its influence law on subsequent coal seams mining, the isomer was firstly determined as the collapse column by means of 3D seismic, transient electromagnetic detection, SYT detection and other methods, and its development characteristics, conductivity and water enrichment were identified.Then FLAC3D numerical simulation software was used to analyze the characteristics of vertical stress and plastic failure zone in different coal seams during mining.Finally, by comparing the ultimate failure depth of floor and the thickness of waterproof layer in the process of each coal seam directly pushing through the collapse column, the risk of water inrush and the prevention are analyzed.The results show that the exposed geological isomer is characterized by weak water-rich collapse column.Under the influence of the mining of the previous coal seam and the activation of the collapse column, the subsequent coal seam is in the low stress area before mining, which increases the floor failure and causes the activation of the collapse column more easily during mining.Coal 5# and 4# can be directly pushed through the collapse column, and coal pillar of sufficient width should be left for coal 1# to prevent the collapse column from activating water inrush.

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Research on application of mine transient electromagnetic method in detecting collapse column

Journal of Physics Conference Series ◽

10.1088/1742-6596/2076/1/012100 ◽

2021 ◽

Vol 2076 (1) ◽

pp. 012100

Author(s):

Hailong Du ◽

Wen Li ◽

Jinsong An ◽

Lin Zhang ◽

Weiye Zhao ◽

...

Keyword(s):

Electromagnetic Method ◽

Shanxi Province ◽

Transient Electromagnetic Method ◽

Transient Electromagnetic ◽

Working Face ◽

Geological Conditions ◽

Collapse Column ◽

Control Work ◽

Research On Application ◽

Mine Transient Electromagnetic Method

Abstract The transient electromagnetic detection has been widely applied to mine roadway excavation engineering. In order to figure out the front geological conditions of roadway excavation, the application of mine transient electromagnetic method (TEM) in detecting collapse column was conducted in this paper by taking the TEM-based advanced detection of 53152 working face in a mine located in Jincheng, Shanxi Province as an example. The results showed that if TEM is applied, geological structures like water-free collapse column could be largely delineated. Besides, by combining the interference source of detection environment and related geological data nearby the detection site, ‘false abnormalities’ could be effectively eliminated, thus providing the reference basis for the water prevention and control work of mines.

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Comprehensive Exploration and three-dimensional construction technology of water plug based on directional horizontal drilling caved column

E3S Web of Conferences ◽

10.1051/e3sconf/202123703003 ◽

2021 ◽

Vol 237 ◽

pp. 03003

Author(s):

Gan Tian

Keyword(s):

Water Inrush ◽

Three Dimensional ◽

Comprehensive Treatment ◽

Filling Material ◽

Distribution Characteristics ◽

Horizontal Drilling ◽

3D Geological Modeling ◽

Working Face ◽

Fracture Area ◽

Collapse Column

The ordovician limestone water inrush accident occurred during the excavation of 8228 working face in Tashan Coal Mine, Tongmei Group. On the basis of comprehensive geophysical exploration above and below the well, in order to find out the development boundary of the water flowing subsided column and the distribution characteristics of the broken body filled in it, and to control the subsided column by Grouting, the development boundary, the influence zone, the cementation of the fractured body and the distribution characteristics of the water flowing subsided column are found out by means of multi-layer and multi-branch surface directional horizontal drilling speed logging, drilling fluid leakage, cuttings logging and logging while drilling, and combined with data statistical analysis. The length and short axis of the collapse column is 410m - 200m, and the broken area is mainly distributed in the right front of the driving head of the belt roadway near the water inrush roadway. The 3d geological modeling of the spatial structure and development characteristics of the collapse column is carried out by using SURPAC software, and the main passageway area, fracture area and secondary fracture area are divided according to the crushing degree of the collapse column filling material. In view of the different zones of the collapse column broken body, the directional horizontal drilling control technology and the three-dimensional block grouting technology are used to construct the separate zones of the grouting technology. The safe mining of the working face is finally realized by the comprehensive treatment of cutting the source and reinforcing the water-flowing collapse column. The comprehensive exploration and treatment technology of directional horizontal drilling multi-branch collapse column provides a good reference for other similar projects.

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Study on attenuation coefficient characteristics of the in-seam seismic wave in fault and collapse column

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/585/1/012016 ◽

2020 ◽

Vol 585 ◽

pp. 012016

Author(s):

Lian Yuguang ◽

Wei Jinshan ◽

Li Wen ◽

Jiao Yang ◽

Dou Wenwu ◽

...

Keyword(s):

Attenuation Coefficient ◽

Seismic Wave ◽

Collapse Column

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Failure Depth of a Floor of a Fully Mechanized Working Face When Passing a Collapse Column

Advances in Civil Engineering ◽

10.1155/2018/9406839 ◽

2018 ◽

Vol 2018 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Jinlong Cai ◽

Min Tu ◽

Wensong Xu

Keyword(s):

Water Injection ◽

Structural Defects ◽

Concentration Coefficient ◽

Working Face ◽

Floor Failure ◽

Before And After ◽

Mining Face ◽

Collapse Column ◽

Failure Depth ◽

Water Injection Test

The stress change law of a collapse column and the failure depth of a coal seam floor before and after mining when the fully mechanized coal mining face passes through the collapse column are investigated. Here, we present the constructed program in FISH language, render the damage variable in FLAC3D to establish the numerical model, and complete the numerical calculation. The 10–115 working faces that pass the collapse column at a coal mine in Tuanbai are identified as the research object. The floor failure is numerically simulated to assess the damage. The following results were obtained: the failure depth of the full floor is stabilized at 14.6 m; the maximum failure depth of the floor near the collapse column is 18.2 m; and the stress concentration coefficient is 1.27 times greater than that of normal mining. The calculated depth failure of the floor of the working face without structural defects is 14.6–14.7 m based on the Hoek–Brown criterion. With the collapse column, the failure depth of the floor is 16.8–17.8 m. According to the water injection test, the maximum failure depth of the floor is 18 m. The three derived values agree well with one another.

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Study on Wave Field Characteristics and Imaging of Collapse Column in Three-Dimensional Detection with Love Channel Wave Reflected outside the Working Face

Open Journal of Geology ◽

10.4236/ojg.2020.1011048 ◽

2020 ◽

Vol 10 (11) ◽

pp. 1027-1039

Author(s):

Huachao Sun ◽

Huide Zhang ◽

Jinyun Wang ◽

Xianzhuang Lv ◽

Xin Ding ◽

...

Keyword(s):

Wave Field ◽

Three Dimensional ◽

Working Face ◽

Channel Wave ◽

Collapse Column

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Geological Structure Exploration of Karst Collapse Column and Evaluation of Water Insulation Properties of the Mud Part

Geofluids ◽

10.1155/2021/2071333 ◽

2021 ◽

Vol 2021 ◽

pp. 1-9

Author(s):

Shijian Yu ◽

Jiyang Liu ◽

Peng Bai ◽

Hongtao Xu ◽

Runshan He ◽

...

Keyword(s):

Water Inrush ◽

Splitting Method ◽

Geological Structure ◽

Karst Collapse ◽

Electrical Characteristics ◽

X Ray Diffraction ◽

Working Face ◽

Mineral Compositions ◽

Collapse Column ◽

Brazilian Splitting

In this study, the X5 KCC in Shiquan Coal Mine was investigated by means of controlled source audio magnetotelluric exploration and borehole television. In this way, the subsection geological structure of the KCC was obtained. Next, the geological and electrical characteristics of each part were analyzed, and it is concluded that the development status of the mud part under coal seam floor is the key part to judging whether water inrush will occur during working face recovery under aquifer pressure. Furthermore, the mineral compositions of purplish-red mudstone and lime mudstone were obtained by performing an X-ray diffraction experiment on the KCC interstitial materials. On this basis, the water insulation properties of the mud part were qualitatively evaluated. Finally, the tensile strength of the mud part was obtained by the Brazilian splitting method, and the water insulation ability of the mud part at the periods when the tunneling roadway and the working face passed the KCC was calculated, respectively. The research results boast guiding significance for safe recovery of the working face passing KCCs under aquifer pressure.

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