Surrounding Rock Classification in Deep Roadway of Coal Mine

2011 ◽  
Vol 181-182 ◽  
pp. 242-246 ◽  
Author(s):  
Bin Liu ◽  
Quan Sheng Liu
Keyword(s):  
Coal Mine ◽  
Surrounding Rock ◽  
Support Design ◽  
Geological Investigation ◽  
Rock Classification ◽  
Rock Stability ◽  
Mining Depth ◽  
Deep Rock ◽  
Ground Stress ◽  
The Stability

With the increase of mining depth，most coals in China have been deep mining stage. Compared to the shallow roadway, the characteristics of deformation-failure of surrounding rock show significant differences in the deep roadway, and the deep rock features of the surrounding rock are not considered in the traditional classification of roadway. So it is needed that systematical study on the surrounding rock classification for the stability evaluation of the deep roadway to meet the demand of the support design and the construction of the deep roadway in coal mine of China. The paper puts forward classification system of surrounding rock in deep roadway of coal mine according to on-the-spot geological investigation, rock ultrasonic testing, in-situ ground stress testing and comprehensive analysis on the surrounding rock stability of deep roadway in typical ore area.

scholarly journals Study on the Instability Characteristics and Bolt Support in Deep Mining Roadways Based on the Surrounding Rock Stability Index: Example of Pansan Coal Mine

2020 ◽  
Vol 2020 ◽  
pp. 1-16 ◽  
Author(s):  
Jucai Chang ◽  
Kai He ◽  
Zhiqiang Yin ◽  
Wanfeng Li ◽  
Shihui Li ◽  
...  
Keyword(s):  
Coal Mine ◽  
Stability Index ◽  
Surrounding Rock ◽  
Full Length ◽  
Control Effect ◽  
Support Design ◽  
Rock Stability ◽  
Working Face ◽  
The Stability ◽  
Bolt Support

In view of the influence of mining stress on the stability of the surrounding rock of inclined roof mining roadways in deep mines, the surrounding rock stability index is defined and solved based on the rock strength criterion and the stress distribution. The mining roadway of the 17102(3) working face of the Pansan Coal Mine is used as the engineering background and example. The surrounding rock’ stabilities under the conditions of no support and bolt support are analyzed according to the surrounding rock’s stability index and the deformation data. The results show that the areas of low wall and high wall instability are 1.68 m2 and 2.12 m2, respectively, and the low wall is more stable than the high wall; the areas of the roof and floor instability are 0.33 m2 and 0.35 m2, respectively, and the roof and floor are more stable than the two sides. During mining, the area of instability greatly increases at first, then decreases to 0, and reaches a maximum value at the peak of the abutment pressure. The stability of the surrounding rock decreases first and then increases. Compared with the end anchoring bolt support, the full-length anchoring bolt support reduces the area of instability to a greater extent, and the full-length anchoring bolt support effect is better. The surrounding rock in the end anchoring zone and the full-length anchoring zone began to deform significantly at 200 m and 150 m from the working face, respectively. This indicates that the control effect of the full-length anchoring bolt support is better and verifies the rationality of the surrounding rock stability index to describe the instability characteristics. This research method can provide a theoretical reference for analysis of the stability characteristics and support design of different cross-section roadways.

Geo-Stress Measurement and its Application in the Yangchangwan Coal Mine

2013 ◽  
Vol 353-356 ◽  
pp. 398-402
Author(s):  
Xiao Yu Zhang ◽  
Feng Ming Liu ◽  
Gang Chen
Keyword(s):  
Stability Analysis ◽  
Coal Mine ◽  
Basic Parameter ◽  
Stress Measurement ◽  
Three Dimensional ◽  
Stress Relief ◽  
Tectonic Stress ◽  
Surrounding Rock ◽  
Support Design ◽  
Rock Stability

The initial stress of rock is a basic parameter, which can be used for surrounding rock stability analysis, exploitation and support design. By utilizing stress relief method of hollow inclusion with its characters of high precision and obtaining three dimensional stress at one time, we have measured three dimensional stress magnitude and direction in north wing roadway (-850m) and 710 open-off cut (-1000m), respectively. The results show that the horizontal tectonic stress is obvious in this coal area.

Stress Distribution Characteristics in Rock Surrounding Heading Face and its Relationship with Temporary Supporting

2014 ◽  
Vol 568-570 ◽  
pp. 1684-1689
Author(s):  
Zhong Han Chen
Keyword(s):  
Coal Mine ◽  
Surrounding Rock ◽  
Zenith Distance ◽  
Rock Stability ◽  
Coal Roadway ◽  
Temporary Support ◽  
The Stability ◽  
Roadway Deformation ◽  
Mine Roof ◽  
Roof Deformation

To solve the problem of underground tunneling face from the empty top, using FLAC3D analysis software, surrounding rock stability for coal roadway 2-1121 of Ganhe Coal Mine are analyzed in numerical calculation. (1) During the tunneling, distance drivage face head-on 0.5-1m at the roof of roadway deformation and destruction features are more obvious, the two sides of roadway are even more significant. (2) Ganhe Coal Mine roof deformation has been established with different empty the experience formula of the zenith distance, obtained Ganhe underground tunneling face reasonable empty zenith distance is 3.5m. (3) Temporary support can obviously reduce roof deformation, reduce thickness of plastic zone of the top, to improve the stability of surrounding rock tunneling faces.

Optimization of Stope Structural Parameters in Phosphorite Mine and its Stability Analysis

2014 ◽  
Vol 580-583 ◽  
pp. 1268-1272 ◽  
Author(s):  
Xiang Xing Li ◽  
Ke Gang Li
Keyword(s):  
Structural Parameters ◽  
Simulation Method ◽  
Surrounding Rock ◽  
Room And Pillar Mining ◽  
Rock Stability ◽  
Mining Depth ◽  
Ground Pressure ◽  
Pillar Mining ◽  
Phosphate Deposit ◽  
The Stability

A mine plans to exploit the low dip thin phosphate deposit by room-and-pillar mining. But a township highway is just above the orebody, and its distance is only 80m, in order to better control the ground pressure in stopes and ensure the operation security, the size of room and pillar must be reasonably designed to maintain the stability of stopes and surrounding rock. The 3D-σ numerical simulation method was applied to analyze the surrounding rock stability in different stope structure parameters. The results show that when holding the size of pointed prop unchanged, the surrounding rock stability would decline with the increase of room width and pillar spacing, for security, the mining plan, the pointed prop is 3×3 m, the stope width and pillar spacing is not more than 9 m, were considered to be one of the optimal. In addition, it is important to emphasize that if the mining depth exceeds 300m, some methods, such as decreasing the spacing of stope and pointed props or increasing the pillar size, need to be taken to avoid the stope instability caused by greater ground pressure.

Research on High Ground Stress and Soft Rock Roadway Supporting Technology of Bide Coal Mine

2012 ◽  
Vol 446-449 ◽  
pp. 2156-2161
Author(s):  
Yong Dong Jiang ◽  
Ling Xiong ◽  
Wei Xin Zhou ◽  
Xing Jiang Han ◽  
Shi Xing Mei ◽  
...  
Keyword(s):  
Coal Mine ◽  
Soft Rock ◽  
Surrounding Rock ◽  
Parameters Optimization ◽  
Rock Classification ◽  
Floor Rock ◽  
Stress Concentration Region ◽  
Ground Stress ◽  
Soft Rock Roadway ◽  
Rock Roadway

This paper， based on the distortion and failure character of soft rock Roadway in Bide coal mine, analyzed deformation and failure mechanisms of soft rock roadway that all are effected by factors of ground stress, lithology, mining influence, unreasonable support parameters and water. The new supporting scheme and parameters optimization of roadway were presented by means of ground stress measurement, mechanics parameters determination of roof and floor rock, monitoring of anchor-hold and result of surrounding rock classification. Then, through numerical simulation, this paper analyzed how the new supporting scheme could control the deformation of surrounding rock effectively, reduce tress in periphery area of surrounding rock, and decrease the stress concentration region of roadway, and prevent the base angle rock mass from macro shear slipping. The field examination results showed that the new supporting scheme was feasible, which can ensure the stability of roadway, with no consequences like roof falls, rib spalling and floor heave.The research results can be used as reference to design supporting structure in high ground stress soft rock roadway .

scholarly journals Risk Analysis and Extension Assessment for the Stability of Surrounding Rock in Deep Coal Roadway

2019 ◽  
Vol 16 (23) ◽  
pp. 4752
Author(s):  
Chunjing Gao ◽  
Dongmei Huang ◽  
Xikun Chang ◽  
Han Xi
Keyword(s):  
Rock Mass ◽  
Risk Analysis ◽  
Coal Mine ◽  
Element Model ◽  
Surrounding Rock ◽  
Deep Mine ◽  
Factors Affecting ◽  
Rock Stability ◽  
The Stability ◽  
Hazard Sources

In order to evaluate the surrounding rock stability of deep roadways, the diversity of accident hazard sources in deep coal mining is statistically analyzed. To conduct an effective evaluation, first, the risk analysis of the factors affecting the rock mass accidents is carried out, and the comprehensive safety index system of rock accidents in deep mine roadway is established. Further, combining the theory of hazard sources with the extension method, a matter–element model for the risk assessment of rock mass accidents in deep roadway is established. Finally, the hazard sources for the surrounding rock stability of deep roadway in the E-Zhuang coal mine of Xinwen Ming area are evaluated. The results show that the risk grade of the surrounding rock for deep roadways in E-Zhuang coal mine is “B”, which is generally safe, the human factors and organizational management factors are relatively safe, and some suggestions for improvement are put forward.

scholarly journals Study on instability failure mode and monitoring early warning standard of surrounding rock in fully weathered argillaceous sandstone section of large section tunnel

2019 ◽  
Vol 136 ◽  
pp. 04023
Author(s):  
Ming Zhao ◽  
Ke Li ◽  
Hong Yan Guo ◽  
KaiCheng Hua
Keyword(s):  
Limit State ◽  
Stable State ◽  
Simulation Software ◽  
Surrounding Rock ◽  
Large Section ◽  
Rock Stability ◽  
Geological Conditions ◽  
Construction Step ◽  
The Face ◽  
The Stability

Based on the special geological conditions of a tunnel in Qingyuan section of Huizhou-Zhanzhou Expressway, FLAC3d numerical simulation software is used to simulate the rheological properties and instability of surrounding rock in large-section fully weathered sandstone section, and the stability and loss of surrounding rock are analyzed. The deformation of the dome and the face at steady state is analyzed. It is found that: 1) when the surrounding rock is in a stable state, the deformation curve of the dome is smooth. When the surrounding rock of the face is unstable, the front of the face appears ahead. Deformation should be first strengthened on the surrounding rock in front of the face. 2) The arched foot is an important part of the instability of the surrounding rock. In order to prevent the expansion of the collapsed part, the arched part should be reinforced. 3) In order to obtain the limit state of surrounding rock stability, the strength of surrounding rock is reduced, and the strength reduction coefficient corresponding to the displacement sudden point is taken as the safety factor of rock stability around the hole, and the stability safety coefficients of surrounding rock of each construction step are greater than 1.2. 4) The dynamic standard values of deformation control in the whole construction stage are obtained by analyzing the deformation curves of each data monitoring point with time in the corresponding time period of each construction step.

Application of ABAQUS in Surrounding Rock Stability Analysis of Shallow Large Cross-Section Tunnel

2015 ◽  
Vol 777 ◽  
pp. 8-12 ◽  
Author(s):  
Lin Zhen Cai ◽  
Cheng Liang Zhang
Keyword(s):  
Numerical Simulation ◽  
Rock Mass ◽  
Strong Support ◽  
Surrounding Rock ◽  
Tunnel Engineering ◽  
Tunnel Excavation ◽  
Rock Stability ◽  
Rock Bolting ◽  
Excavation Support ◽  
The Stability

HuJiaDi tunnel construction of Dai Gong highway is troublesome, the surrounding-rock mass give priority to full to strong weathering basalt, surrounding rock integrity is poor, weak self-stability of surrounding rock, and tunnel is prone to collapse. In order to reduce disturbance, taking advantage of the ability of rock mass, excavation adopt the method of "more steps, short footage and strong support". The excavation method using three steps excavation, The excavation footage is about 1.2 ~ 1.5 m; The surrounding rock bolting system still produce a large deformation after completion of the first support construction, it shows that the adopted support intensity cannot guarantee the stability of the tunnel engineering. Using ABAQUS to simulate tunnel excavation support, optimizing the support parameters of the tunnel, conducting comparative analysis with Monitoring and Measuring and numerical simulation results, it shows that the displacement - time curves have a certain consistency in numerical simulation of ABAQUS and Monitoring and Measuring.

scholarly journals Study of the Stability Control of the Rock Surrounding Double-Key Strata Recovery Roadways in Shallow Seams

2019 ◽  
Vol 2019 ◽  
pp. 1-21 ◽  
Author(s):  
Cheng Zhu ◽  
Yong Yuan ◽  
Zhongshun Chen ◽  
Zhiheng Liu ◽  
Chaofeng Yuan
Keyword(s):  
Engineering Application ◽  
Stability Control ◽  
Surrounding Rock ◽  
Control Effect ◽  
Pressure Relief ◽  
Support Design ◽  
Key Strata ◽  
Fracture Development ◽  
Surrounding Rock Control ◽  
The Stability

The stability control of the rock surrounding recovery roadways guarantees the safety of the extraction of equipment. Roof falling and support crushing are prone to occur in double-key strata (DKS) faces in shallow seams during the extraction of equipment. Therefore, this paper focuses on the stability control of the rock surrounding DKS recovery roadways by combining field observations, theoretical analysis, and numerical simulations. First, pressure relief technology, which can effectively release the accumulated rock pressure in the roof, is introduced according to the periodic weighting characteristics of DKS roofs. A reasonable application scope and the applicable conditions for pressure relief technology are given. Considering the influence of the eroded area on the roof structure, two roof mechanics models of DKS are established. The calculation results show that the yield load of the support in the eroded area is low. A scheme for strengthening the support with individual hydraulic props is proposed, and then, the support design of the recovery roadway is improved based on the time effects of fracture development. The width of the recovery roadway and supporting parameters is redesigned according to engineering experience. Finally, constitutive models of the support and compacted rock mass in the gob are developed with FLAC3D software to simulate the failure characteristics of the surrounding rock during pressure relief and equipment extraction. The surrounding rock control effects of two support designs and three extraction schemes are comprehensively evaluated. The results show that the surrounding rock control effect of Scheme 1, which combines improved support design and the bidirectional extraction of equipment, is the best. Engineering application results show that Scheme 1 realizes the safe extraction of equipment. The research results can provide a reference and experience for use in the stability control of rock surrounding recovery roadways in shallow seams.

scholarly journals Study on Stability of Round Tunnel Surrounding Rock

2018 ◽  
Vol 175 ◽  
pp. 04016
Author(s):  
NIU Yan ◽  
Ji Yafei ◽  
Wang Zhao
Keyword(s):  
Evaluation Criteria ◽  
Surrounding Rock ◽  
Rock Stress ◽  
Stress Release ◽  
Circular Tunnel ◽  
Tunnel Excavation ◽  
Finite Element Software ◽  
Rock Stability ◽  
The Stability ◽  
Surrounding Rock Stress

Tunnel excavation will lead to the immediate surrounding rock unloading caused by the surrounding rock stress release, the stability of the surrounding rock have a certain impact. In this paper, finite element software ANSYS and finite difference software FLAC3D are used to simulate the excavation and lining process of circular tunnel. The influence of excavation on the rock stability around circular tunnel is analyzed, and the effect of applying lining on the stability of surrounding rock is analyzed. Evaluation criteria selection hole displacement, stress and plastic area of three factors.

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