Optimization of Height Prediction of Water Fractured Zone Based on ANN

2015 ◽  
Vol 737 ◽  
pp. 422-427
Author(s):  
Zhong Ming Zhao ◽  
Yong Liang Liu ◽  
Yi Li
Keyword(s):  
Coal Seam ◽  
Prediction Method ◽  
Geological Condition ◽  
Fractured Zone ◽  
Working Face ◽  
Face Length ◽  
Height Prediction ◽  
Bp Neural Network Model ◽  
Bp Model ◽  
Technical Guidance

This paper discussed the factors that affect the height of water fractured zone, and they were divided into primary and secondary factors, in order to construct a system that included factors that affect the height of water fractured zone. By using the BP neural network model, this paper chose the thickness of coal seam, roof lithology, tilt angle of coal seam, overburden hardness, working face length, advance speed and rock bulking to be the primary factors in order to simplify the model and accelerate speed. If the mining geological condition was clear, we could ignore the secondary factors. Prediction results showed that the simplified BP model could meet the accuracy of the height prediction of water fractured zone and the prediction method could provide technical guidance and a certain safety for coal mining under water.

The Adaptation Analysis of the Fully Mechanized Coal Mining Face of Huopu Mine’s Third Soft Coal Seam

2014 ◽  
Vol 1049-1050 ◽  
pp. 335-338 ◽  
Author(s):  
Fa Quan Liu ◽  
Xue Wen Geng ◽  
Yong Che ◽  
Xiang Cui
Keyword(s):  
Coal Seam ◽  
Coal Mining ◽  
Geological Condition ◽  
Soft Coal ◽  
Working Face ◽  
Mining Face ◽  
Soft Coal Seam ◽  
Working Resistance

To get the maximum coal in front of the working face of the 17# coal seam, we installed a longer beam which is 1.2m in length in the leading end of the original working face supports ZF3000/17/28, and know that working face supports’ setting load and working resistance are lower .We changed the original supports with shield supports ZY3800/15/33 that are adaptable in the geological condition and got the favorable affection.

Determination Method of the Supporting Intensity of Fully-Mechanized Face in Deeply Inclined Medium-Thickness Seam

2014 ◽  
Vol 522-524 ◽  
pp. 1386-1389
Author(s):  
Zhong Ping Guo ◽  
Hui Qiang Duan ◽  
Fan Feng ◽  
Gui Yin Zhang
Keyword(s):  
Coal Seam ◽  
Theoretical Basis ◽  
Surrounding Rock ◽  
Medium Thickness ◽  
Working Face ◽  
Displacement Thickness ◽  
Face Length ◽  
Working Resistance ◽  
Theory Calculation ◽  
The Relationship

According to the occurrence conditions of deeply inclined coal seam of 81206 working face in Yanya coal mine, methods including transmission rock theory calculation and numerical calculation based on the relationship between supports and surrounding rock are used to calculate and analyze. The proper working resistance of support is 5979.2kN and the supporting intensity is 0.8~0.95MPa. The regression equation associated with roof subsidence displacement , thickness of the coal seam, working face length and supporting intensity is accomplished, which provides theoretical basis for the support selection.

The Application of Similar Material in the Simulation of Overlying Strata Movement in High Inclined Seam in Dongbaowei Mine

2012 ◽  
Vol 600 ◽  
pp. 194-198 ◽  
Author(s):  
Ming Ming Wen
Keyword(s):  
Coal Seam ◽  
Reference Value ◽  
Geological Condition ◽  
Similar Material ◽  
Strata Movement ◽  
Support Measures ◽  
Working Face ◽  
Overlying Strata Movement ◽  
Similar Material Simulation ◽  
Overlying Strata

Studying on the characteristics of the overlying strata movement in high inclined coal seam, the similar material is applied in the simulation model which was built based on the similar material simulation theory and high inclined seam geological condition of Dongbaowei coal mine. The picture and displacement of overlying strata were obtained from the similar material simulation. As a result, the characteristics of the fracture and movement of overlying strata above the full mechanized working face in high inclined seam. This paper proposes some support measures to improve the safety of the working face. These provide significance theoretical guidance and reference value for other working face in high inclined seam.

scholarly journals Study on Deformation and Failure Characteristics of Weak Cemented Roof in Shallow and Extra Thick Coal Seam Mining

2021 ◽  
Author(s):  
Chang Liu ◽  
Pingsong Zhang ◽  
Duoxi Yao ◽  
Yuancaho Ou ◽  
Yutong Tian
Keyword(s):  
Coal Seam ◽  
Apparent Resistivity ◽  
Maximum Height ◽  
Geoelectric Field ◽  
Electrical Method ◽  
Deformation And Failure ◽  
Fractured Zone ◽  
Working Face ◽  
Seam Mining ◽  
Loose Layer

Abstract Detecting the development height of water flowing fractured zone in the roof of coal seam is of great significance for the roof safety of working face with developed sandstone and thick loose layer. This paper analyzes the influence of the induced polarization effect of electrode on the traditional single-mode parallel electrical method. In order to avoid this interference, the dual-mode parallel electrical method is applied to monitor the roof deformation and failure of a coal mine in Ordos Basin. The monitoring results show that: under the influence of mining, the change of geoelectric field of coal seam roof is dynamic, the apparent resistivity of initial mining fracture is high, the apparent resistivity of surrounding rock water filling mining fracture is low, and the apparent resistivity of fracture water flowing to goaf is high again. According to the characteristics of geoelectric field, the maximum height of water flowing fracture zone is 122 M; The average mining coal thickness of the working face is 11 m, and the fracture / mining thickness ratio is 11.1. The results of plastic zone show that the maximum height of water flowing fractured zone above the working face is 122 m, which is consistent with the test results. The vertical stress response characteristics of roof monitoring points are zonal. Under the influence of mining, the loose layer near the surface above the working face is cracked. The edge type ground fissures exist for a long time, and there are a series of geological problems such as soil erosion, ground subsidence.

scholarly journals Migration Law of the Roof of a Composited Backfilling Longwall Face in a Steeply Dipping Coal Seam

Minerals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 188 ◽  
Author(s):  
Wenyu Lv ◽  
Yongping Wu ◽  
Liu Ming ◽  
Jianhui Yin
Keyword(s):  
Coal Seam ◽  
Inclination Angle ◽  
Mechanical Model ◽  
Surrounding Rock ◽  
Longwall Face ◽  
Mining Operations ◽  
Mining Depth ◽  
Working Face ◽  
Face Length ◽  
Migration Law

The artificial-caved rock composited backfilling approach can effectively restrain the dynamic phenomena in the coal seam and the associated roof and floor during mining operations, and can also improve the stability of the system of support and surrounding rock. In this study, based on the analysis of influencing factors affecting the surrounding rock movement and deformation of the composited backfilling longwall face in a steeply dipping coal seam, the roof mechanical model is developed, and the deflection differential equation is derived, to obtain the roof damage structure and the location of the roof fracture for the area without backfilling. The migration law of the roof under different inclination angles, mining depths, working face lengths, and backfilling ratios are analyzed. Finally, mine pressure is detected in the tested working face. Results show that the roof deflection, bending moment, and rotation drop with the increase of the inclination angle and backfilling ratio, whereas these parameters increase with greater mining depth and working face length. The roof failure location moves toward the upper area of the working face as the inclination angle and working face length increases, while it moves toward the center of the non-backfilling area with greater mining depth and backfilling ratio. Results from the proposed mechanical model agree well with the field test results, demonstrating the validity of the model, which can provide theoretical basis for a safe and efficient mining operation in steeply dipping coal seams.

Numerical Analysis of Influencing Factors of Stability in Thick Coal Seam Mining Roadway

2012 ◽  
Vol 256-259 ◽  
pp. 1453-1457
Author(s):  
Zhi Hua Li ◽  
Xin Zhu Hua ◽  
Ke Yang ◽  
Ruo Jun Zhu ◽  
De Sheng Zhou
Keyword(s):  
Coal Seam ◽  
Abutment Pressure ◽  
Surrounding Rock ◽  
Rock Body ◽  
Thick Coal Seam ◽  
Mining Depth ◽  
Working Face ◽  
Face Length ◽  
Seam Mining ◽  
Mining Height

The FLAC-3D software was used to study the surrounding rock displacement and the side abutment pressure distribution laws about roadway in thick coal seam. Based on this model, through change the mining height, working face length and mining depth, the differences of roadway underground pressure characteristics were analyzed between thick coal seam working face and normal working face. The results indicate that: ①the displacement of roadway surrounding rock increases with the increase of mining depth and mining height, the closer to the coal wall the larger of the increase range of roadway displacement. ②the peak of side abutment pressure increases with the increase of mining depth and mining height, the peak district of the stress will move toward the inner department of rock body. ③ the effect of working face length on the roadway displacement and the side abutment pressure is very feeble.

scholarly journals A Gas Seepage Modeling Study for Mitigating Gas Accumulation Risk in Upper Protective Coal Seam Mining Process

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Cun Zhang ◽  
Lei Zhang ◽  
Mingxue Li ◽  
Chen Wang
Keyword(s):  
Coal Seam ◽  
Field Measurements ◽  
Interlayer Spacing ◽  
Mitigation Measures ◽  
Plastic State ◽  
Geological Condition ◽  
Gas Emission ◽  
Working Face ◽  
Gas Seepage ◽  
Seam Mining

Protective coal seam mining (PCSM) is one of the most significant mitigation measures of regional outburst in the process of deep coal seam mining, which has high outburst risk in China. During the PCSM process, the phenomenon of methane concentration exceeding the limit usually occurs in the working face. It is vital to understand factors affecting gas emission from the protective seam working face (PSWF) and to obtain an equation for determining the quantity of gas emission. A gas seepage model (GSM) was developed to simulate the gas emission during the process of upper PCSM. In this study, an equation was formulated to determine the quantity of gas desorbed from the protected seam into PSWF. These equations have been developed by using Fick’s second law of diffusion and Darcy’s flow law. The relationship between permeability and stress was described in an elastic-plastic state, and the mechanics of surrounding rock were investigated. It can be concluded from GSM that the initial gas pressure of protected seam, the characteristics of interlayer rocks, and the ventilation pressure of PSWF were the main factors that influenced the desorption of gas emission from the protected seam into PSWF. The developed GSM was tested for calculating gas emission quantity from the PCSM process by utilizing the actual geological condition data of a coal mine, which is located in Hancheng, China. The results have shown great agreement with obtained field measurements, which is done by combining the fitting curve of ventilation air methane quantity for PSWF with an interlayer spacing. A loss coefficient (δ) of 1.012 × 10−3 was obtained in this study.

scholarly journals Complete methodology to resist in mechanism longwall mine 6# at Nam Mau Coal Company

2019 ◽  
Vol 61 (1) ◽  
pp. 116-123
Author(s):  
Nguyen Phi Hung ◽  
Nguyen Cao Khai ◽  
Bui Manh Tung ◽  
Lai Quang Trung ◽  
Tran Van Thang ◽  
...  
Keyword(s):  
Coal Seam ◽  
Coal Mines ◽  
Field Measurements ◽  
Longwall Face ◽  
Support Pressure ◽  
Geological Condition ◽  
Hydraulic Support ◽  
Working Face ◽  
Calculation Results ◽  
Longwall Mine

Geological condition of 6# at Nam Mau coal mines is very complicated for mechanism longwall method, specialy was cause of is the cause of difficulties in moving hydraulic support, so it is necessary to have appropriate reform solutions for the support equipment to operate effectively. The result of dynamic field measurements at the site shows that the maximum support pressure is from 5 to 10 m in front of the mechanism longwall. The coal seam area is located close to the working face due to the influence of the support pressure and beyond the durable limit which was in an unconsolidated state, so it is possible to cause the mirror landslide and topping out. Calculation results show that the distance of 15 m against advance reinforcement at the junction of the furnace head and foot furnace as designed. The results of the study of the distribution of surrounding longwall face pressure, length of longwall need longer 40 meters.

A Case Study on Development of Water-flow Fractured Zone During Close-Distance Repeated Coal Mining

2021 ◽  
Author(s):  
Yuanzhong Luan ◽  
Yaofan Shi ◽  
Shui Yu ◽  
Yue Dong ◽  
Yong Yan
Keyword(s):  
Coal Seam ◽  
Coal Mining ◽  
Water Flow ◽  
Water Injection ◽  
Scientific Basis ◽  
Hole Drilling ◽  
Fractured Zone ◽  
Working Face ◽  
Distance Working ◽  
Close Distance

Abstract The upper and lower seam of seam No.3 of some coal mines in Shandong Province are in close proximity which can be regards as close-distance coal seam mining.This paper takes the close-distance working face of Fucun coal mine as engineering background and mainly focuses on the investigation and research on inaccuracy of the forecasting and incompetence of the developing principles of water-flow fractured zone(WFFZ)during close-distance coal seam group mining.First,calculations on the height of WEEZ by adopting empirical formula.And FLAC3D software was established to calculate the height of the overburden WFFZ after repeated mining of the upper and lower seam of seam No.3.At the same time,using the double-ended water plugging observation technology of downhole drilling and upward hole drilling by analyzing the water injection loss ratio of the reference hole and the post-mining hole,the accurate numerical values of the WFFZ and the ratio of WFFZ height to mining height(W-M ratio)are obtained.The comparative analysis shows that the numerical simulation results are close to the measured ones,and the empirical formula is not applicable to the near-distance repeated mining.Finally,the prediction model is established based on the measured height of the WFFZ of multiple working faces,which provides a scientific basis for further exploring the development law of the overlying rock in underwater coal mining and ensuring the safe mining of coal seams at close distances.

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