scholarly journals Engineering design of selecting particle size of gangue under solid backfill mining for protecting water resources

2020 ◽  
Vol 24 (6 Part B) ◽  
pp. 4019-4026
Author(s):  
Yun Zhang ◽  
Peng-Fei Shan ◽  
Rui Bai ◽  
Jing-Jing Dai
Keyword(s):  
Water Resources ◽  
Mechanical Model ◽  
Ecological Environment ◽  
Deformation Characteristics ◽  
Mining Method ◽  
Working Face ◽  
Backfill Mining ◽  
Beams On Elastic Foundation ◽  
Solid Backfill Mining ◽  
Overlying Strata

In view of the ecological environment damages caused by the loss of water resources and the gangue accumulation during coal mining, this paper proposed a solid backfill mining method to recover the coal seam under the water body, which could fundamentally reduce the sinking space of the overlying strata, and better prevent water-flowing fractures expanding. Consequently, according to the deformation characteristics of the overlying strata of the solid backfill mining, a mechanical model was established for superimposed beams on elastic foundation with simu?lating the expansion water-flowing fractures under solid backfill mining. A method of calculating the height of the water-flowing fractured zone was provided, and the mechanical mechanism of the development of water-flowing fractures in the overlying strata under solid backfill mining was expressed. Meanwhile, the backfill rate of the experimental working face was designed as 80% to avoid the ecological environment damages caused by gangue accumulation. The stress-strain characteristics of gangue samples under different grading size schemes were further studied.

Study on Surface Movement and Deformation Characteristics and Pillar Stability of Large Strip Mining under Deep Mining

2013 ◽  
Vol 734-737 ◽  
pp. 531-534
Author(s):  
Jun Tao Chen ◽  
Kai Kai Sheng ◽  
Li Min Yin ◽  
Chuan Qiang Wu
Keyword(s):  
Practical Significance ◽  
Strip Mining ◽  
Deformation Characteristics ◽  
Mining Technology ◽  
Pillar Stability ◽  
Deep Mining ◽  
Surface Movement ◽  
Working Face ◽  
Movement And Deformation ◽  
Overlying Strata

Large strip mining technology could effectively control the surface subsidence inducing from overlying strata movement and realize green mining. Bored stress and deformation sensors were laid in 4301 working face pillar of Shandong energy zibo mining group tangkou coal, analyzing the strip pillar stress pre and post working face; numerical simulation was used to study the influence of overlying strata from reserved size of strip pillar. According to the observation results of surface movement and deformation, law of surface movement and deformation characteristics was studied, which contributed to the practical application of large strip mining technology under deep mining and had the important theoretical and practical significance for mining under buildings ,railways and water in Chinese.

scholarly journals Research on Overlying Strata Control of Longitudinal and Latitudinal Filling Mining

2021 ◽  
Author(s):  
Fuyu zhang ◽  
Zhongping Guo ◽  
Chengqian He ◽  
Chao Leng
Keyword(s):  
Ground Surface ◽  
Mining Method ◽  
Control Effect ◽  
Practical Applications ◽  
Mining Policy ◽  
Mechanics Model ◽  
Working Face ◽  
Filling System ◽  
Excellent Control ◽  
Overlying Strata

Abstract Abstract: In order to solve the problem of "three unders" coal resources and respond to the national green mining policy, combining with the advantages of short wall strip filling and long wall strip filling, we propose a longitude and latitude filling mining method with high recovery ratio and simple operation,where a latitude and longitude filling network is gradually constructed behind the working face to control the subsidence of the overlying strata.This article introduces the filling system, technological process and filling pipeline layout of the latitude and longitude filling mining method, and constructs the latitude and longitude filling mechanics model by using the elastic foundation theory, and gives the calculation formula for the roof subsidence and the stress of the filling body.By means of numerical simulation,the control of the longitudinal and latitudinal filling overburden was researched.The influence of the quality of the filling, the width of the filling, the spacing of the filling on the roof subsidence and the reasonable filling parameters of the 1207 working face were determined.The roof subsidence, the stress of the filling body and the deformation of the ground surface during the mining process were monitored by means of field monitoring, and the excellent control effect of the latitude and longitude filling mining on the overlying strata is confirmed in practical applications.

The Optimization Research of Wide Strip and Full-Pillar Mining under Villages

2012 ◽  
Vol 616-618 ◽  
pp. 406-410
Author(s):  
Gui Liu ◽  
Hua Xing Zhang ◽  
Jin Hui Chen ◽  
Chao Gao
Keyword(s):  
Surface Structures ◽  
Strip Mining ◽  
Mining Method ◽  
Sequence Optimization ◽  
Wide Strip ◽  
Deformation Limit ◽  
Working Face ◽  
Specific Analysis ◽  
Pillar Mining ◽  
Coal Pillars

By making full use of the advantages of strip mining method and full-pillar mining method, the wide strip and full-pillar mining method can achieve the aim of mining under villages. However, at the full-pillar mining stage, the difficulty in managing several workfaces which are at work at the same time still exists. To improve the wide strip and full-pillar mining method’s applicability, an optimization of extraction sequence for coal pillars instead of the multi-working-face is put forward at the stage of full-pillar mining, and in the case of the deformation limit of surface structures is satisfied, to extract all the coal pillars which are under villages. By specific analysis of the extraction sequence optimization of the coal pillars in No.1 mine under Qian Xudapo village which belongs to Chang Chun coal Co., LTD., a better result is got which also acts a technological reference for the extraction under villages.

scholarly journals Physical Modeling of the Controlled Water-Flowing Fracture Development during Short-Wall Block Backfill Mining

Lithosphere ◽  
2021 ◽  
Vol 2021 (Special 4) ◽  
Author(s):  
Yun Zhang ◽  
Yongzi Liu ◽  
Xingping Lai ◽  
Jianming Gao
Keyword(s):  
Coal Pillar ◽  
Similarity Criterion ◽  
Test Results ◽  
Control Effect ◽  
Physical Similarity ◽  
Wall Block ◽  
Fracture Development ◽  
Backfill Mining ◽  
Backfill Materials ◽  
Overlying Strata

Abstract Short-wall block backfill mining (SBBM) technology is an effective method to solve the environmental problems in the mining process. Based on the technical characteristics of SBBM technology and the physical similarity criterion, the physical similarity models for comparing the control effects of water-flowing fracture (WFF) development using short-wall block cave mining (SBCM) and SBBM were established, and the deformation and the WFF development of overlying strata above gob were monitored. The test results determined that the composite materials of 5 mm thick pearl sponge+5 mm thick sponge+10 mm thick paper+6 mm thick board were adopted as the similar backfill materials by comparing the stress-strain curves between the similar backfill materials and the original gangue sample. When the backfilling body was filled into the gob, it would be the permanent bearing body, which bore the load of the overlying strata accompanied with the protective coal pillar. At the same time, the backfilling body also filled the collapse space of overlying strata, which was equivalent to reduce the mining height, and effectively reduced the subsidence and failure height of the overlying strata. Compared with SBCM, the test results showed that the maximum vertical deformation, the height of water-flowing fractured zone, and activity range of overlying strata using SBBM were reduced by 91.4%, 82.5%, and 64.9%, respectively. SBBM had a significant control effect on strata damage and WFF development, which could realize the purpose of water resource protection in coal mines.

scholarly journals Research and Application of an Innovative 110 Mining Method in Gob-Side Half Coal Rock Entry Retaining

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Eryu Wang ◽  
Xiangdong Chen ◽  
Xiaojie Yang
Keyword(s):  
Recovery Rate ◽  
Mine Pressure ◽  
Mining Method ◽  
Time Consumption ◽  
Coal Recovery ◽  
Working Face ◽  
Constant Resistance ◽  
Movement Characteristic ◽  
Coal Rock ◽  
Maximum Subsidence

In order to solve the problems of the high cost and time consumption of half coal rock entry driving, low coal recovery rate, and stress concentration on filling support body of retained entry along gob, the innovative 110 mining method based on pressure relief by roof cutting was adopted in 6302 thin coal seam working face of Baoshan Coal Mine. First the technical principle and key technology of this mining method was presented. Then, through theoretical analysis and calculation, engineering experience, and field test, the key parameters such as the length of constant resistance anchor cable, the cutting angle and height of presplitting blasting, the charge structure, and the blocking-gangue support structure were determined and conducted in the retained entry. The broken expanded coefficient varying law of caved gangue with time and space was obtained, which revealed roof movement characteristic. The displacement monitoring curve of the roof and floor indicated that the maximum subsidence of the roof was about 150 mm and the maximum amount of floor heaving was 100 mm, which were quite small. The field monitoring data indicated that the entry retaining effect is good, which indicated that the innovative 110 mining method can be an effective way for reducing the high cost and time consumption of half coal rock entry driving, enhancing the coal recovery rate and preventing the dynamic mine pressure disasters.

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.

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