scholarly journals A Case Study of Optimization and Application of Soft-Rock Roadway Support in Xiaokang Coal Mine, China

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Shuai Guo ◽  
Xun-Guo Zhu ◽  
Xun Liu ◽  
Hong-Fei Duan
Keyword(s):  
Soft Rock ◽  
Surrounding Rock ◽  
Geological Conditions ◽  
Floor Heave ◽  
Roadway Support ◽  
Soft Rock Roadway ◽  
Surrounding Rock Stress ◽  
Rock Roadway

The roadway of S2S2 fully mechanized caving face (FMCF) in Xiaokang Coal Mine is one of the most typical deep-buried soft-rock roadways in China and had been repaired several times. In order to figure out the failure reasons of the original roadway support, the geological conditions were investigated, the surrounding rock stress was monitored, the rib displacement, roof separation, and floor heave were in situ measured, and the performance of the U-shaped steel support was simulated. The above analysis results indicated that the support failure was mainly caused by (1) the unreasonable arch roadway section, (2) the high and complex surrounding rock stress, (3) the failure control of the floor heave, and (4) the inadequate self-supporting capacity of the surrounding rock. For optimizing, the roadway section was changed to circle and a new full-section combined support system of “belt-cable-mesh-shotcrete and U-shaped steel-filling behind the support” was adopted, which could specifically control the floor heave, allow the roadway deformation in control, and improve the self-supporting ability and stress field of the surrounding rock. To determine the support parameters, the selected U-shaped steel support was verified by simulation, and various bolt-cable support schemes were simulated and compared. Finally, such an optimized support scheme was applied in the roadway of the next replacement FMCF. The in situ monitoring showed that the rib-to-rib convergence and roof-to-floor convergence were both controlled within 600 mm, which indicated that the roadway was effectively controlled. This case study has important reference value and guiding function for the optimal design of the soft-rock roadway support with similar geological conditions.

Research and Exploration on Combined Support Technology in Deep Soft-Rock Roadway

2012 ◽  
Vol 594-597 ◽  
pp. 616-620
Author(s):  
Lian Wei Ren ◽  
Guang Yong Wang ◽  
Long Wang
Keyword(s):  
Systems Engineering ◽  
High Stress ◽  
Soft Rock ◽  
Physical And Mechanical Properties ◽  
Surrounding Rock ◽  
Construction Technology ◽  
Geological Conditions ◽  
Roadway Support ◽  
Soft Rock Roadway ◽  
Rock Roadway

Because of the existence of high stress in the surrounding rock of deep roadway, the physical and mechanical properties of the surrounding rock to change, and the surrounding rock stress distribution is very different from the shallow, so the way of shallow roadway support is not suitable for deep roadway. Deep soft-rock roadway support is a complex systems engineering, it should consider the different geological conditions, roadway scope of application, construction technology conditions, construction period and the cost and other factors to determine the optimal combined support program, if the special geological conditions encountered in the construction, it should be timely to improve the supporting program to meet the construction safety and ensure the quality. This paper is based on the characteristics of deep roadway support, sums up the combined support form in the project, researches and analyzes the combined support technology, and explores how to use suitable combined support form in deep roadway.

Numerical Simulation of Bolt-Mesh-Anchor Support Technology at Soft Rock Roadway

2013 ◽  
Vol 868 ◽  
pp. 251-254 ◽  
Author(s):  
Hui Yu ◽  
Ling Gen Kong ◽  
Zhi Yong Niu ◽  
Shi Ting Zhu ◽  
Dan Yang Jing
Keyword(s):  
Simulation Analysis ◽  
Soft Rock ◽  
Confining Pressure ◽  
Surrounding Rock ◽  
Numerical Software ◽  
The Stability ◽  
Roadway Deformation ◽  
Soft Rock Roadway ◽  
Surrounding Rock Stress ◽  
Rock Roadway

The roof of 12501 transportation roadway of Tunlan mine is friable. To solve the problem of large roadway deformation, the bolt-mesh-anchor support scheme is put forward. With the FLAC3D numerical software in the program, the simulation analysis shows that the program can effectively increase the roadway confining pressure to improve the state of the surrounding rock stress, reduce roadway displacement and deformation and thus keep the stability of the surrounding rock. The results show that Bolt and cable support can effectively control the surrounding rock, with the roadway convergence rate small, and the support system safe.

scholarly journals Failure Mechanism Analysis and Support Design for Deep Composite Soft Rock Roadway: A Case Study of the Yangcheng Coal Mine in China

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Bangyou Jiang ◽  
Lianguo Wang ◽  
Yinlong Lu ◽  
Shitan Gu ◽  
Xiaokang Sun
Keyword(s):  
Failure Mechanism ◽  
Coal Mine ◽  
Failure Mechanisms ◽  
Soft Rock ◽  
Deformation Monitoring ◽  
Surrounding Rock ◽  
Support Design ◽  
Soft Rock Roadway ◽  
Rock Roadway

This paper presented a case study of the failure mechanisms and support design for deep composite soft rock roadway in the Yangcheng Coal Mine of China. Many experiments and field tests were performed to reveal the failure mechanisms of the roadway. It was found that the surrounding rock of the roadway was HJS complex soft rock that was characterized by poor rock quality, widespread development of joint fissures, and an unstable creep property. The major horizontal stress, which was almost perpendicular to the roadway, was 1.59 times larger than the vertical stress. The weak surrounding rock and high tectonic stress were the main internal causes of roadway instabilities, and the inadequate support was the external cause. Based on the failure mechanism, a new support design was proposed that consisted of bolting, cable, metal mesh, shotcrete, and grouting. A field experiment using the new design was performed in a roadway section approximately 100 m long. Detailed deformation monitoring was conducted in the experimental roadway sections and sections of the previous roadway. The monitoring results showed that deformations of the roadway with the new support design were reduced by 85–90% compared with those of the old design. This successful case provides an important reference for similar soft rock roadway projects.

Study on Surrounding Rock Deformation Characteristics and Control Technology in Deep Soft Rock Roadway

2012 ◽  
Vol 594-597 ◽  
pp. 631-635 ◽  
Author(s):  
Wen Hua Zha ◽  
Xin Zhu Hua
Keyword(s):  
Soft Rock ◽  
Surrounding Rock ◽  
Control Technology ◽  
Deformation Characteristics ◽  
Control Effect ◽  
Tunnel Support ◽  
Technical Problems ◽  
Geological Conditions ◽  
Soft Rock Roadway ◽  
Rock Roadway

To explore support technical problems in deep soft rock roadway, according to deep complicated geological conditions in 102 transport rise of Yuandian Mine, obtaining deformation characteristics of roadway in the initial support scheme under conditions, analysing the reasons of instability and failure of surrounding rock, proposing the surrounding rock control technology of step-by-step strengthen co-supporting, determining secondary anchor cable strengthen support time and grouting delay distance, optimizing the parameters of roadway support. Industrial practice show that the control effect of deformation was obvious,which provide the reference for deep soft rock tunnel support decision.

scholarly journals Instability Mechanism and Key Control Technology of Deep Soft Rock Roadway under Long-Term Water Immersion

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Wei Jing ◽  
Xu Wang ◽  
Pengwei Hao ◽  
Laiwang Jing ◽  
Weipei Xue
Keyword(s):  
Water Immersion ◽  
Soft Rock ◽  
Surrounding Rock ◽  
The Self ◽  
Instability Mechanism ◽  
Roadway Support ◽  
Soft Rock Roadway ◽  
Bearing Structure ◽  
Rock Roadway

More and more attention has been paid to the supporting problem of deep soft rock roadway floor with long-term water immersion in recent years. However, the existing soft rock roadway support technology rarely takes into account the influence of the immersion softening phenomenon of the roadway floor and the self-supporting structure characteristics of the surrounding rock on the stability of the surrounding rock at the same time, and the influence of the creep characteristics of rock on the deformation zone of the surrounding rock requires further research on the nature and division of the self-supporting structure of the surrounding rock. In response to the issues mentioned, based on the loading and unloading properties of the surrounding rock of the soft rock roadway, a new concept of the internal and external self-bearing structure was proposed. The fact of water-immersed mudstone softening in the soft rock roadway floor was revealed through the field practice, and the shape of the internal and external bearing structure was determined based on the in situ monitoring results. Then, the instability mechanism of the internal and external self-bearing structure of the surrounding rock was analyzed, the position of the critical control point was calculated, and the key control technology based on the method of controlling floor heave by using double-row anchor cables to control the deformation of the roadway sides was put forward. Finally, the field industrial test showed that this support technology can effectively control the deformation and failure of soft rock roadway in the case of water immersion on the floor. This work can provide a technical reference for similar roadway support designs.

Application of Grouting Reinforcement Technology in Pingshan Shaft Station

2014 ◽  
Vol 580-583 ◽  
pp. 1347-1351
Author(s):  
Liang Tian ◽  
Jing Yi Xi ◽  
Jian Liu ◽  
Xiao Dong Liu ◽  
Feng Shang ◽  
...  
Keyword(s):  
Roof Rock ◽  
Soft Rock ◽  
Difficult Problem ◽  
Surrounding Rock ◽  
Ground Pressure ◽  
Geological Conditions ◽  
Floor Heave ◽  
Cable Force ◽  
Grouting Reinforcement ◽  
Roadway Support

Support of soft rock is a big challenge in all mines at home and abroad. Soft rock is of different kinds of rheological property for geological conditions, mine ground pressure and so on. It brings about really difficult problem to roadway support. In order to ensure safety application and prolong usage, shaft station need to be reinforced. Sight instrument was used to analyze broken conditions. The results show that the broken depth in roof rock is 5~6 m, and greater than 4 m in sidewalls. According to failure characters and sight results, we determine that rock of shaft station belongs to high geo-stress and jointed soft rock. On this basis, technology of grouting reinforcement combined with cable anchor support is carried out. Monitoring results of surface convergence and cable force show that bearing capacity of surrounding rock increases obviously, roadway contraction and floor heave are well controlled.

Brief Analysis of Floor Grouting Method in Soft Rock Roadway Based on Engineering Materials and Engineering Mechanics

2013 ◽  
Vol 345 ◽  
pp. 442-446 ◽  
Author(s):  
Peng Wei Hao ◽  
Hai Long Dong ◽  
Zhao Hui Liu ◽  
Jing Pei Li ◽  
Lai Wang Jing
Keyword(s):  
Free Water ◽  
Soft Rock ◽  
Practical Method ◽  
Floor Heave ◽  
Influence Of Water ◽  
Engineering Mechanics ◽  
Soft Rock Roadway ◽  
Surrounding Rock Stress ◽  
Rock Roadway

Floor grouting in soft rock roadway is one of the effective ways in floor heave control, and this method is being promoted quietly and quickly, but the applying effect is far from satisfied, the reasons are that: the depth of floor grouting is not enough and the influence of water hiding in floor hasnt been attached great importance. This paper analyzed the characteristics of floor broken rock zone in soft rock roadway and pointed out the importance of floor grouting in soft rock roadway, then proposed a practical method of floor grouting. The analysis conclusions show that: the depth of floor broken rock zone that can reach more than 4m is much greater than that of roof broken rock zone due to the double influences of surrounding rock stress and water; the important role of floor grouting in soft rock roadway is draining off free water from broken rock zone in order to strengthen roadway floor; floor grouting includes three important steps: plugging water channels, pumping out free water and grouting in deep holes. The article has revealed common blind spots of floor grouting methods existing, the method this article has noted can solve floor heave of soft rock roadway well, and it has very good application prospects. Key words: soft rock roadway, floor grouting, broken rock zone, free water in floor

Research to Enhance the Supporting Stiffness of Different U-Type Sheds

2012 ◽  
Vol 256-259 ◽  
pp. 892-895
Author(s):  
Yu Cheng Zhao ◽  
Dan Feng Lu ◽  
Ya Bin Zhen
Keyword(s):  
Mechanical Properties ◽  
Soft Rock ◽  
Surrounding Rock ◽  
Stress Increase ◽  
Simulation And Optimization ◽  
Mining Depth ◽  
Angle Change ◽  
Roadway Support ◽  
Soft Rock Roadway ◽  
Rock Roadway

With the increase of the mining depth, the surrounding rock of roadways shows the characteristics of soft rock that the stress increase, poor rock cementation, broken loose, a significant expansion, creep deformation, etc. Deep roadways mainly use the combination of active and passive supporting method, U-type shed is widely used in the roadway support and becomes gradually the main supporting form. This paper studies mechanical properties of different arched U- type sheds, then compares the stress distribution and the displacement change. According to the result of simulation and optimization, it is seen that the deformation trend is regular with the angle change, and when θ=30°, the U- type shed is better in the roadway support. The conclusion can provide some theoretical guidance for the deep or soft rock roadway support.

scholarly journals A Case Study on Large Deformation Failure Mechanism and Control Techniques for Soft Rock Roadways in Tectonic Stress Areas

2019 ◽  
Vol 11 (13) ◽  
pp. 3510 ◽  
Author(s):  
Xue ◽  
Gu ◽  
Fang ◽  
Wei
Keyword(s):  
Numerical Simulation ◽  
Large Deformation ◽  
Failure Mechanism ◽  
Support System ◽  
Soft Rock ◽  
Tectonic Stress ◽  
Geological Conditions ◽  
Soft Rock Roadway ◽  
Rock Roadway

Large deformation and failure of soft rock are pressing problems in the mining practice. This paper provides a case study on failure mechanisms and support approaches for a water-rich soft rock roadway in tectonic stress areas of the Wangzhuang coal mine, China. Mechanic properties of rock mass related to the roadway are calibrated via a geological strength index method (GSI), based on which a corresponding numerical simulation model is established in the Universal Discrete Element Code (UDEC) software. The failure mechanism of the roadway under water-saturating and weathering conditions is revealed by field tests and numerical simulation. It is found that the stress evolution and crack development are affected by weathering and horizontal tectonic stresses. The roadway roof and floor suffer from high stress concentration and continuous cracking, and are consequently seen with rock failure, strength weakening, and pressure relief. Unfortunately, the current support system fails to restrain rock weathering and strength weakening, and the roadway is found with serious floor heave, roof subsidence, and large asymmetric deformation. Accordingly, a new combined support system of “bolt–cable–mesh–shotcrete + grouting” is proposed. Moreover, numerical simulation and field testing are conducted to validate the feasibility and effectiveness of the proposed approach, the results of which demonstrate the capacity of the proposed new support method to perfectly control the surrounding rock. Findings of this research can provide valuable references for support engineering in the soft rock roadway under analogous geological conditions.

Sign in / Sign up

Export Citation Format

Share Document