scholarly journals Failure Mechanism and Optimization of Arch-Bolt Composite Support for Underground Mining Tunnel

2020 ◽  
Vol 2020 ◽  
pp. 1-18 ◽  
Author(s):  
Yuchun Mei ◽  
Weiteng Li ◽  
Ning Yang ◽  
Gang Wang ◽  
Tingchun Li ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Failure Mechanism ◽  
Underground Mining ◽  
Failure Process ◽  
Pressure Coefficient ◽  
High Stress ◽  
Soft Rock ◽  
Composite Support ◽  
Soft Rock Roadway ◽  
Rock Roadway

Numerical simulation tests were performed on the arch-bolt combined supported mining tunnel through an improved numerical simulation approach. The typical soft rock roadway was took as the background, and the influencing factors such as ground stress level, lateral pressure coefficient, and support type and parameters were considered. The failure mechanism of a semicircular roadway with two straight walls was analyzed; results showed that the arch legs’ inward bending deformation and the arch-rock separation are the breakthrough of the global failure of the supporting system, and rock bolts breakage promoted the failure process. The effects of different controlling measures were analyzed including enlarging the bolt diameter, replacing the conventional bolts with energy-absorbing bolts, and setting arch locking bolts on the arch legs. The field test of the concrete-filled steel tube (CFST) arch-bolt composite support scheme was carried out in a high-stress soft rock roadway, and the results indicate the reliability of the main conclusions.

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.

High Strength Combined Support Technology in Deep High Stress Soft Rock Roadway

2012 ◽  
Vol 524-527 ◽  
pp. 598-603
Author(s):  
Nian Jie Ma ◽  
Zhi Qiang Zhao ◽  
Hua Zhao ◽  
Li Shuai Jiang
Keyword(s):  
High Stress ◽  
Soft Rock ◽  
High Strength ◽  
Parameter Determination ◽  
Test Results ◽  
Actual Measurement ◽  
Computer Numerical Simulation ◽  
Soft Rock Roadway ◽  
Rock Roadway

In order to solve the serious damage and repeat revision problem of high stress soft rock roadway in deep -950 level of Tangshan coal mine, based on the theory of the maximum stress level, together with the actual measurement of geostress and the laboratory mechanical parameters of rock-core and computer numerical simulation, the high strength combined support technology and supporting parameters are determined and the engineering test has been done. The engineering test results show that the parameter determination of high strength combined support technology, which based on the actual measurement of geostress, can effective solve the support issue of high stress soft rock roadway and provide useful experience for similar engineering problems.

Study on deformation failure mechanism and support technology of deep soft rock roadway

2020 ◽  
Vol 264 ◽  
pp. 105262 ◽  
Author(s):  
Guang Li ◽  
Fengshan Ma ◽  
Jie Guo ◽  
Haijun Zhao ◽  
Gang Liu
Keyword(s):  
Failure Mechanism ◽  
Soft Rock ◽  
Soft Rock Roadway ◽  
Rock Roadway

scholarly journals Deformation Mechanism and Support Technology of Deep and High-Stress Soft Rock Roadway

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Lujing Zheng ◽  
Yujun Zuo ◽  
Yafei Hu ◽  
Wei Wu
Keyword(s):  
Mechanical Properties ◽  
Bearing Capacity ◽  
High Stress ◽  
Soft Rock ◽  
Physical And Mechanical Properties ◽  
Surrounding Rock ◽  
Rock Fragmentation ◽  
The Stability ◽  
Soft Rock Roadway ◽  
Rock Roadway

In this study, the analysis and control of stability of surrounding rock in deep fractured soft rock roadway located in the underground mine of Jinfeng gold mine in Guizhou Province, China, has been investigated. The surrounding rock of roadway has been analyzed to characterize its deformation and failure mechanism through field survey, testing of rock physical and mechanical properties, in situ stress measure, analysis of mineral components of rock, and investigation of rock fragmentation degree. Based on the numerical simulation technology, the influence of different factors on the stability of roadway is studied. The physical and mechanical properties of surrounding rock and the bearing capacity of surrounding rock layer are to be improved to maintain the stability of broken soft rock roadway as high ground stress, rock fragmentation, and poor lithology leading to tunnel instability. Hence, a high-strength “cable bolt + fiber-reinforced shotcrete + steel mesh + split sets + resin bolt + cement grouting” combined support system has been proposed to improve the effective bearing structure significantly with high integrity and bearing capacity.

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.

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