scholarly journals Nonlinear Large Deformation Mechanism and Stability Control of Deep Soft Rock Roadway: A Case Study in China

2019 ◽  
Vol 11 (22) ◽  
pp. 6243 ◽  
Author(s):  
Dong Wang ◽  
Yujing Jiang ◽  
Xiaoming Sun ◽  
Hengjie Luan ◽  
Hui Zhang
Keyword(s):  
Large Deformation ◽  
Coal Mine ◽  
Deformation Mechanism ◽  
Soft Rock ◽  
Stability Control ◽  
Surrounding Rock ◽  
Gansu Province ◽  
Soft Rock Roadway ◽  
Coupling Support ◽  
Rock Roadway

Improving the safety and stability of soft surrounding rock with nonlinear large deformation gives a strong guarantee for the safe mining and sustainable development of deep coal mines. In order to control the nonlinear large deformation of the surrounding rock in a deep soft rock roadway, this paper discusses the nonlinear large deformation mechanism and coupling support countermeasures of a typical engineering application at Xin’an coal mine in Gansu province, China. The series of experiments and theoretical analysis described in this paper reveal the phenomena, properties, and reasons for the nonlinear large deformation of soft surrounding rock in detail. Then, the type of nonlinear large deformation mechanism is determined and transformed from a composite one to a simple one. Based on experimental results and mechanism transformation, a suitable coupling support countermeasure, which contains the Constant Resistance Large Deformation (CRLD) bolt, steel mesh, floor hollow grouting cable, and steel fiber concrete, is proposed to reduce the nonlinear large deformation and the potential risk during mining. The application shows that the coupling support countermeasure can effectively reduce the nonlinear large deformation of the surrounding rock and help to maintain the stability of the deep soft rock roadway at Xin’an coal mine.

Investigation on Deformation and Failure Characteristics and Stability Control of Soft Rock Roadway Surrounding Rock in Deep Coal Mine

2011 ◽  
Vol 255-260 ◽  
pp. 3711-3716 ◽  
Author(s):  
Ju Cai Chang ◽  
Guang Xiang Xie
Keyword(s):  
Coal Mine ◽  
Plastic Region ◽  
Soft Rock ◽  
Stability Control ◽  
Surrounding Rock ◽  
Failure Characteristics ◽  
Deformation And Failure ◽  
Deep Coal Mine ◽  
Soft Rock Roadway ◽  
Rock Roadway

Numerical simulation and field measurement were carried out to investigate into laws of deformation and movement and the evolving characteristics of the plastic region around the roadway based on engineering conditions of deep soft rock roadway in Wangfenggang colliery, Huainan Mining area. The mechanism of controlling the surrounding rock stability of soft rock roadway in deep coal mine was demonstrated. The supporting of soft rock roadway in deep coal mine must be compatible with deformation and failure characteristics of surrounding rock, and it can keep the stability of surrounding rock. The combined supporting with high strength and prestress bolting-anchoring and integral surrounding rock grouting reinforcement can effectively control the surrounding rock deformation of soft rock roadway in deep coal mine. But every working step must be pay attention to sequence on the time and space so that it can play an integral supporting effect. Research results are put into practice accordingly and good control effect has been achieved.

Strength Assessments of Concrete-Filled Steel Tubular Support of Soft Rock Roadway

2013 ◽  
Vol 838-841 ◽  
pp. 1884-1890 ◽  
Author(s):  
Guang Long Qu ◽  
Yan Fa Gao ◽  
Liu Yang ◽  
Bin Jing Xu ◽  
Guo Lei Liu ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Coal Mine ◽  
Soft Rock ◽  
Surrounding Rock ◽  
Flexural Performance ◽  
Laboratory Test Results ◽  
Different Types ◽  
Soft Rock Roadway ◽  
Core Concrete ◽  
Rock Roadway

Compared with I-shaped and U-shaped supports in soft rock roadway, concrete-filled steel tubular (CFST) support, as a new supporting form, has stronger bearing capacity with reasonable price. So it is becoming more and more popular in roadway supporting of coal mine in China. In this article, the surrounding rock in soft rock roadway was classified into three different types: hard rock in deep coal mine, soft surrounding rock, extremely soft surrounding rock. And, according to the characteristics of deformation failure of the CFST support and the surrounding rock in the industrial tests, three different strength assessments, including assessment of axial compressive strength, assessment of lateral flexural performance, assessment of hardening rate of core concrete, were proposed through mechanical analysis and laboratory tests for the three different types of the surrounding rock, respectively. Moreover, aimed to insufficient flexural strength of the support or low hardening rate of the core concrete in some of the roadway supporting, strengthening lateral flexural performance or making early strength concrete was necessary for the above unfavorable situations. The laboratory test results showed that the ultimate bearing capacity for the CFST support with φ194*8mm of steel tube reinforced by φ38mm round steel was 31% greater than that of the unreinforced one, 177% greater than that of the U-shaped one with equivalent weight per unit length.

Study on Stability for Intersection of Deep Soft Rock Roadway

2011 ◽  
Vol 243-249 ◽  
pp. 2666-2669
Author(s):  
Zhan Jin Li ◽  
Yang Zhang ◽  
Xue Li Zhao
Keyword(s):  
Coal Mine ◽  
Soft Rock ◽  
Intersection Problem ◽  
The Third ◽  
Geological Conditions ◽  
Control Stability ◽  
Soft Rock Roadway ◽  
Crossing Point ◽  
Coupling Support ◽  
Rock Roadway

With the depth increasing continuously, more complicated of geological conditions, will make intersection in deep soft rock roadway is very difficult to support. In order to solve the intersection problem of difficult to support, combined with the third levels of the Fifth Coal Mine of Hemei, the coupling supporting design—anchor-mesh-cable + truss to control stability of crossing point—is proposed. Based software of FLAC3D, simulate the program applicable in deep soft rock roadway intersection. Application results show that the coupling support technology of anchor-mesh-cable + truss can effectively control the deformation of intersection in deep soft rock roadway.

scholarly journals A Study of Soft Rock Roadway Coupling Support in Xiajing Coal Mine

2014 ◽  
Vol 84 ◽  
pp. 812-817
Author(s):  
Li Xuefeng ◽  
Cheng Guihai ◽  
Li Xiaoquan ◽  
Zhang Ruichong
Keyword(s):  
Coal Mine ◽  
Soft Rock ◽  
Soft Rock Roadway ◽  
Coupling Support ◽  
Rock Roadway

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.

A case study on large deformation failure mechanism of deep soft rock roadway in Xin'An coal mine, China

2017 ◽  
Vol 217 ◽  
pp. 89-101 ◽  
Author(s):  
Sheng-Qi Yang ◽  
Miao Chen ◽  
Hong-Wen Jing ◽  
Kun-Fu Chen ◽  
Bo Meng
Keyword(s):  
Large Deformation ◽  
Failure Mechanism ◽  
Coal Mine ◽  
Soft Rock ◽  
Soft Rock Roadway ◽  
Rock Roadway

scholarly journals Constant-Resistance, Rigid, and Flexible Coupling Support Technology for Soft Rock Entrances in Deep Coal Mines:A Case Study in China

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Yong Zhang ◽  
Chengwei Zhao ◽  
Ming Jiang ◽  
Jiaxuan Zhang ◽  
Chen Chen ◽  
...  
Keyword(s):  
Large Deformation ◽  
Support System ◽  
Soft Rock ◽  
High Strength ◽  
Surrounding Rock ◽  
Constant Resistance ◽  
The Stability ◽  
Control Principle ◽  
Soft Rock Roadway ◽  
Rock Roadway

The stability control of a soft rock roadway is a crucial problem for sustainable utilization of limited coal resources in deep mining practices. To solve it, the soft rock types and failure mechanism of −890 entrance surrounding rock have been analyzed, taking Daqiang Coal Mine of China as an engineering example. The analysis shows that the damage to the surrounding rock was characterized by asymmetry, large deformation, severe damage, and extended durations. The surrounding rock can be divided into high-stress-jointed-strong expansion soft rock based on S-M scanning and mineral analysis. Numerical simulation is used to reproduce the failure process of the original supporting system and analyze the deformation of the surrounding rock, range of plastic zone, and distribution of the stress field. The failure mechanism is thus defined for a deep soft rock roadway. Combined with the above studies, the deformation mechanics of the surrounding rock is summarized as type IABIIABIIIABC. The stability transformation mechanism of the surrounding rock is proposed, based on which the control principle of deformation stability of a surrounding rock is formed. According to the control principle, “high strength support controls the surrounding rock deformation. The large deformation of the flexible support system releases the accumulated energy to the surrounding rock, and long-term deformation of the surrounding rock is controlled by high strength truss support.” Meanwhile, the constant-resistance, rigid, and flexible coupling (CRRFC) support system is proposed. The numerical analysis demonstrated that the CRRFC support system can effectively reinforce the shallow surrounding rock and improve the bearing capacity. Simultaneously, the development of the surrounding rock malignant plastic zone is effectively controlled. The application results show that the large deformation of the roadway can be effectively controlled by the CRRFC support system, which provides applications for similar engineering.

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 .

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