Study on Large Inclined Angle Integrated Caving Hydraulic Support Stability Control

2013 ◽  
Vol 744 ◽  
pp. 121-123
Author(s):  
Yong Qiang Yue ◽  
Chun Xia Sun ◽  
Peng Fei Liu ◽  
Xiang Hui Meng
Keyword(s):  
Coal Seam ◽  
Face Processing ◽  
Stability Control ◽  
Practical Application ◽  
Hydraulic Support ◽  
Strained Condition ◽  
Working Face ◽  
Main Factors ◽  
The Stability ◽  
Inclined Angle

Analyzed the main factors of affecting hydraulic support stability, this paper analyses anti-topple and antiskid technology to apply to inclined angle 15~33°and compatible supports ZF4200/16/26. Through the practical application in shanjia mine, it can meet large inclined angle mine demands. The follows were studied that can influence the stability of support in large inclined angle coal seam. Every roof situation in the direction of large inclined angle suffering different stress lead to different caving property, and the roof motivation can affect other supports strained condition and stability. Caving mechanism behind the caving coal support suffer downward force, and the force is put on caving shield and tail beam, so it makes supports generate angle of bank. The support would lose its stability with working face processing and supports advancing for descending support and losing point of support.

scholarly journals Mechanical Modeling of Roof Fracture Instability Mechanism and Its Control in Top-Coal Caving Mining under Thin Topsoil of Shallow Coal Seam

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Peilin Gong ◽  
Tong Zhao ◽  
Kaan Yetilmezsoy ◽  
Kang Yi
Keyword(s):  
Coal Seam ◽  
Mechanical Model ◽  
Main Roof ◽  
Stability Control ◽  
Hydraulic Support ◽  
Rock Stability ◽  
Shallow Coal Seam ◽  
Minimum Height ◽  
The Stability ◽  
Working Resistance

This study aimed to explore the safe and efficient top-coal caving mining under thin topsoil of shallow coal seam (SCS) and realize the optimization of hydraulic support. Numerical simulation and theoretical analysis were used to reveal the stress distribution of the topsoil, the structure characteristics of the main roof blocks, and the development of the roof subsidence convergence. Step subsidence of the initial fractured main roof after sliding destabilization frequently existed, which seriously threatened the safety of the hydraulic supports. Hence, a mechanical model of the main roof blocks, where the topsoil thickness was less than the minimum height of the unloading arch, was established, and the mechanical criterion of the stability was achieved. The working resistance of the hydraulic support was calculated, and the reasonable type was optimized so as to avoid crushing accident. Findings of the present analysis indicated that the hydraulic support optimization was mainly affected by fractured main roof blocks during the first weighting. According to the block stability mechanical model based on Mohr–Coulomb criterion, the required working resistance and the supporting intensity were determined as 4899 kN and 0.58 MPa, respectively. The ZZF5200/19/32S low-position top-coal caving hydraulic support was selected for the studied mine and support-surrounding rock stability control of thin-topsoil SCS could be achieved without crushing accident.

scholarly journals Stability of "Support-Surrounding Rock" System for Fully Mechanized Longwall Mining in Steeply Dipping Coal Seams

2021 ◽  
Author(s):  
Luo Shenghu ◽  
tong wang ◽  
Wu Yongping ◽  
Huangfu Jingyu ◽  
Zhao Huatao
Keyword(s):  
Coal Seam ◽  
Longwall Mining ◽  
Stability Control ◽  
Surrounding Rock ◽  
Coal Seams ◽  
Physical Test ◽  
Rock System ◽  
Working Face ◽  
The Stability ◽  
Mining Height

Abstract The key to the safe and efficient longwall mining of steeply dipping seams lies in the stability control of the "support-surrounding rock" system. This paper analyzes the difficulty of controlling the stability of the support during the longwall mining process of steeply dipping coal seams in terms of the characteristics of the non-uniform filled-in gob using a combination of physical test, theoretical analysis and field measurements. Considering the floor as an elastic foundation, we built a "support-surrounding rock" mechanical model based on data obtained on "support-surrounding rock" systems in different regions and the laws of support motion under different load conditions. Our findings are summarized as follows. First, depending on the angle of the coal seam, the caving gangue will roll (slide) downward along the incline, resulting in the formation of a non-uniform filling zone in the deep gob in which the lower, middle, and upper sections are filled, half-filled, and empty, respectively. In addition, an inverted triangular hollow surface is formed on the floor of the gob in the middle and upper sections behind the support. Furthermore, as the angle of the coal seam, length of the working face, and mining height increase, the characteristics of the non-uniform filled-in gob are enhanced. Second, we found that, as a result of support by the gangue, the "support-surrounding rock" system is relatively stable in the lower part of the working face while, in the middle and upper sections of the working face, the contact method and loading characteristics of the support are more complicated, making stability control difficult. Third, the magnitude and direction of the load, action point, and mining height all affect the stability of the support to varying degrees, with the tangential load and action position of the roof load having the most significant impacts on the stability of the support. Under loading by the roof, rotation and subsidence of the support inevitably occur, with gradually increasing amplitude and effects on the inter-support and sliding forces. Finally, we found that it is advisable in the process of moving the support to adopt "sliding advance of support" measures and to apply a "down-up" removal order to ensure overall stability. These research results provide reference and guidance of significance to field practice production.

Stability Analysis of Hydraulic Support in Large Inclined and High Mining Height Coalface

2011 ◽  
Vol 101-102 ◽  
pp. 1105-1108 ◽  
Author(s):  
Wei Zhang ◽  
Dong Sheng Zhang ◽  
Yong Shu Zhao
Keyword(s):  
Stability Control ◽  
Coal Seams ◽  
Hydraulic Support ◽  
Support Design ◽  
Geological Conditions ◽  
Support Resistance ◽  
The Stability ◽  
Inclined Angle ◽  
Selection Of ◽  
Mining Height

Under the condition of large inclined angle, the stability control of hydraulic support was always the challenge for the fully-mechanized mining in large inclined coal seams. Based on the specific geological conditions of 509 coalface with large inclined and high mining in Gaozhuang mine, the model of hydraulic support had been drawn by using SolidWorks software, and the inclination mechanical model of hydraulic support had been established to analyze its inclination stability along coalface. The calculation result shows that when the maximum inclination angle is 31° and the underhand angle is 10°, the minimum support resistance needed to keep the hydraulic support not dumping is 283.59 kN. Meanwhile, the critical support resistance required for the hydraulic support not to dump in inclination direction increases approximately linearly along with the increase of coalface mining height; under the same mining height condition, the critical support resistance increases along with the increase of the inclined angle. Therefore, the selection of the mining height and inclined angle of the coal seam must be considered at the beginning of the hydraulic support design.

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.

Study on the Relationship between Hydraulic Support on the Working Face with Large Mining Height and Surrounding Rock

2011 ◽  
Vol 328-330 ◽  
pp. 1671-1674
Author(s):  
Ying Ma ◽  
Sheng Zhong
Keyword(s):  
Coal Seam ◽  
Surrounding Rock ◽  
Hydraulic Support ◽  
Working Face ◽  
Safety Work ◽  
Immediate Roof ◽  
The Face ◽  
Large Mining Height ◽  
The Relationship ◽  
Mining Height

Using unified model and theory of rock pressure, the problems, such as caving of stope roof with large mining height and destruction of support, strata movement and surface subsidence, are unified analyzed and researched. The results show that: pressure shell is dynamic shell, which moves forward with the propulsion of working face; with the increase of mining height on the face, the height of fracture zone in coal seam increases, not continuously, but jumpily; with the increase of mining height, support load rises, but the degree of this rise decreases gradually, increased degree of immediate roof weight should be greater than that of given deformation pressure. The results provide necessary basis for reliability of hydraulic support on the working face with large mining height and safety work in the underground.

Lightweight Design for Hydraulic Support

2010 ◽  
Vol 450 ◽  
pp. 79-82
Author(s):  
Xin Zhang ◽  
Jian Wu Zhang ◽  
Qing Liang Zeng ◽  
Cheng Long Wang
Keyword(s):  
Lightweight Design ◽  
Three Dimensional ◽  
Bottom Plate ◽  
Three Dimensional Model ◽  
Hydraulic Support ◽  
Element Analysis ◽  
Side Plate ◽  
Mining Condition ◽  
The Stability ◽  
Inclined Angle

In large inclined angle mining condition, in order to decrease the effect of sliding force, a lightweight design for hydraulic support is presented in this paper. Taking minimum mass of top beam as optimization objective, the three-dimensional model of it is built firstly. The whole top beam is simplified into top plate, side plate, bottom plate and main reinforcement on the premise of unchanging its topology configuration, and only strength constraint is chosen as constraint, which reduces the number of constraint functions and calculation cycles. By means of ANSYS zero-order optimization module, the mass of top beam is decreased about 16.9%. Finally, the optimal lightweight structure is fully evaluated under the same load as pre-optimization, and finite element analysis results prove that its stress and strain satisfy the need of strength. This lightweight design measure is used in the practical manufacturing with a lower cost of materials, which also increases the stability of hydraulic support in large inclined angle mining condition.

Structure Design of the Hydraulic Support Sprag Units for Great Mining Height

2013 ◽  
Vol 744 ◽  
pp. 118-120
Author(s):  
Li Ping Wang ◽  
Xiao Wei Shao ◽  
Chun Yan Qiu ◽  
Wei Min Huang
Keyword(s):  
Coal Seam ◽  
Structure Design ◽  
Coal Face ◽  
Hydraulic Support ◽  
Unit Structure ◽  
Great Height ◽  
The Stability ◽  
Four Bar Linkage ◽  
Hydraulic Supports ◽  
Mining Height

In this paper,the importance of controlling side fall in great mining height coal face is introduced,and the stability of great mining height coal seam,the types and characteristics of sprag units are researched. Through the study this paper designs and confirms the sprag units structure which is fit for the great mining height hydraulic supports well. Hydraulic support sprag unit structure mainly have two types: simple aticulated type and four-bar linkage type.By the analysis and comparision of the characteristic of retractable type and folding type, the folding sprag units which has better integral rigidity is selected.It also provides the methods and experience for the the design of hydraulic support ,especially for the sprag units design of great height hydraulic supports.

scholarly journals Stability Control of a Goaf-Side Roadway under the Mining Disturbance of an Adjacent Coal Working Face in an Underground Mine

2019 ◽  
Vol 11 (22) ◽  
pp. 6398
Author(s):  
Houqiang Yang ◽  
Changliang Han ◽  
Nong Zhang ◽  
Changlun Sun ◽  
Dongjiang Pan ◽  
...  
Keyword(s):  
Stress Distribution ◽  
Stability Control ◽  
Surrounding Rock ◽  
Engineering Practice ◽  
Key Strata ◽  
Coal Recovery ◽  
Working Face ◽  
Underground Coal Mines ◽  
Mining Disturbance ◽  
The Stability

Goaf-side roadway driving could not only notably reduce the loss of coal resources and improve the coal recovery rates, but also greatly mitigate the imbalance between excavation speed and production needs, which are able to prolong the service life of the mine and are pivotal to sustainable and efficient development of underground coal mines. However, it is difficult to control the stability of the goaf-side roadway, especially under mining disturbance of another adjacent coal working face. In order to control the stability of the goaf-side roadway, Haulageway 1513 in the Xinyi Coal Mine of China, under mining disturbance, theoretical analysis, numerical simulation, and engineering practice were carried out to reveal the mechanism of overburden key strata fracture, stress distribution, and deformation characteristics of the surrounding rock of the goaf-side roadway due to mining disturbance. Results showed that some key strata above Goaf 1512 did not fracture due to the influence of the strata caving angles. However, these key strata would fracture and break into rock blocks when suffering from mining disturbance of the adjacent coal working face, which changed the stress distribution and increased the deformations of the surrounding rock of the goaf-side roadway. The combined techniques of pressure relief and bolt support were proposed and carried out to control the stability of the goaf-side roadway. Engineering practice indicated that the maximum deformations of the roof and sidewall-to-sidewall were 220 mm and 470 mm, respectively. The deformations of the goaf-side roadway under mining disturbance were efficiently controlled.

scholarly journals Stability Analysis of Roadway Groups under Multi-Mining Disturbances

2021 ◽  
Vol 11 (17) ◽  
pp. 7953
Author(s):  
Yuantian Sun ◽  
Ruiyang Bi ◽  
Qingliang Chang ◽  
Reza Taherdangkoo ◽  
Junfei Zhang ◽  
...  
Keyword(s):  
Coal Mining ◽  
Coal Pillar ◽  
Stability Control ◽  
Surrounding Rock ◽  
Key Strata ◽  
Working Face ◽  
Roadway Stability ◽  
Mining Disturbance ◽  
Mining Face ◽  
The Stability

The roadway stability has been regarded as the main challenging issue for safety and productivity of deep underground coal mines, particularly where roadways are affected by coal mining activities. This study investigates the −740 m main roadway in the Jining No. 2 Coal Mine to provide a theoretical basis for the stability control of the main deep roadway affected by disturbances of adjacent working activities. Field surveys, theoretical analyses, and numerical simulations are used to reveal mechanisms of the coal mining disturbance. The field survey shows that the deformation of roadway increases when the work face advances near the roadway group. Long working face mining causes the key strata to collapse based on the key strata theory and then disturbs the adjacent roadway group. When the working face is 100 m away from the stop-mining line, the roadway group is affected by the mining face, and the width roadway protection coal pillar is determined to be about 100 m. Flac3D simulations prove the accuracy of the theoretical result. Through reinforcement and support measures for the main roadway, the overall strength of the surrounding rock is enhanced, the stability of the surrounding rock of the roadway is guaranteed, and the safe production of the mine is maintained.

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