Study on failure mechanism of roadway with soft rock in deep coal mine and confined concrete support system

Wang, Q.; Pan, Rui; Jiang, Bei; Li, S.C.; He, Manchao; Sun, Huibin; Wang, Lei; Qin, Q.; Yu, Hao; Luan, Yingcheng

doi:10.1016/j.engfailanal.2017.08.003

Cited by 156 publications

(53 citation statements)

References 14 publications

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“…e rigid support resists the huge surrounding rock pressure mainly by increasing the strength and rigidity of the support structure [26]. e flexible support mainly allows the moderate deformation of the surrounding rock and reduces the surrounding rock stress acting on the support structure [27]. e bolt-grouting integration reinforcement is to change the strength of the surrounding rock by grouting in time after the excavation of the surrounding rock and to add the common supporting structure [28].…”

Section: Introductionmentioning

confidence: 99%

Study on Deformation Mechanism and Support Measures of Soft Surrounding Rock in Muzhailing Deep Tunnel

Tao

Cao

Liu

et al. 2020

Advances in Civil Engineering

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The deformation of Muzhailing deep tunnel is about 2.3 m in the process of construction, which is difficult to be controlled by the traditional “anchor-grouting integration” support system. This paper deeply analyzes the geological characteristics, rock mechanics characteristics, and surrounding rock failure characteristics of Muzhailing tunnel. The deformation mechanism and the failure of the support system are analyzed through the numerical simulation, theoretical analysis, and field test. The authors propose support measures suitable for Muzhailing tunnel based on the analysis results. The maximum buried depth is 600 m, and the engineering rock mass at the depth has nonlinear physical and mechanical phenomenon. The maximum principal stress of Muzhailing tunnel is 25.7 MPa, which belongs to high-stress joint swelling soft rock tunnel. The NPR cable can achieve large deformation under the condition of constant support resistance. The authors put forward the coupling support mode of “NPR cable + steel arch frame + concrete,” which is based on the idea of transforming the composite deformation mechanism to a single type. The stress concentration appears in the range of 12 m in the surrounding rock circle, and the lateral and vertical stress distributions are relatively symmetrical after the improved support. The circumferential strain of the surrounding rock is greatly reduced, and the range of strain is reduced by 10%. The field monitoring results show that the new support system can well control the large soft rock deformation of Muzhailing tunnel (0.5 m). The support strategy proposed can effectively control the large deformation and promote the formation of new support concept for deep tunnel.

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Section: Introductionmentioning

confidence: 99%

Study on Deformation Mechanism and Support Measures of Soft Surrounding Rock in Muzhailing Deep Tunnel

Tao

Cao

Liu

et al. 2020

Advances in Civil Engineering

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“…Recently, with the continuous railway and highway construction in China, tunnel engineering has been developing in situations of long, large and deep burial [1][2][3][4][5][6][7]. It is inevitable more long tunnels will be built in soft and weak surrounding rock areas [8][9][10][11][12][13][14]. Large deformation of soft rock mass is one of the common geological hazards when a tunnel passes through soft rock mass [15][16][17], and is also a long-term problem plaguing tunnel construction [18][19][20][21].…”

Section: Introductionmentioning

confidence: 99%

Stress Field Distribution and Deformation Law of Large Deformation Tunnel Excavation in Soft Rock Mass

et al. 2019

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The problem of large deformation is very prominent in deep-buried tunnel excavation in soft rock, which brings serious potential safety hazards and economic losses to projects. Knowledge of the stress field distribution and deformation law is the key to ensuring rational design and safe construction in large deformation tunnels of soft rock. As described in this paper, theoretical analysis, numerical simulation and field monitoring were employed to investigate the surrounding rock stress and displacement state in the Dongsong hydropower station in Sichuan Province, China. The results show that the short-bench construction method can effectively control the deformation of surrounding rock and range of the plastic zone. In order to reserve enough working space, the optimum bench length in the actual construction was 10 to 14 m. The peripheral displacement and plastic radius decreased with the increase of tunnel support strength and the advance of supporting time. The displacement can be effectively controlled by applying the second lining in time at a position about twice the diameter of the hole (16 m) from the working face. A reasonable reserved deformation should be adopted to avoid secondary expanding excavation. The values of different positions in the tunnel laterally and longitudinally may be different, and adjustments are needed according to the actual situation.

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“…In recent years, with the rapid development of the Chinese economy and an increase in investment in infrastructure construction, all kinds of tunnel projects have been rapidly developed [1][2][3][4][5][6]. The increasing number of long, large and deep buried tunnels has brought great challenges to the construction and operation of projects, in which large deformation of the soft rock mass is a prominent problem [7][8][9][10][11][12][13]. According to the literature reports, when complicated and difficult conditions have been encountered in tunnels, large deformation and failure phenomena have often occurred in tunnel projects including cross-section shrinkage, lining cracking, shotcrete spalling, steel arch distortion, etc.…”

Section: Introductionmentioning

confidence: 99%

Physical and Mechanical Characteristics of Soft Rock Tunnel and the Effect of Excavation on Supporting Structure

et al. 2019

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The problem of large deformation is very prominent in deep-buried tunnel excavation in soft rock, which brings serious potential safety hazards and economic losses to projects. The knowledge of deformation law and support measures is the key to ensure the rational design and safe construction in a large deformation tunnel of soft rock. This paper describes rock physical and mechanical tests and field monitoring is employed to investigate the cause and development process of large deformation in Dongsong hydropower station in Sichuan Province, China. The results show that the free expansion rate of the rock sample is 20.0%, the average expansion stress of the rock sample is 11.0 kPa, and the expansibility of the rock is low. Large deformation of surrounding rock mainly comes from the dilatancy effect with high geostress and relaxation deformation with weak support. Shotcrete sealing exposed surrounding rock, and early strength support avoiding water immersion are useful to deal with the three main factors (weathering, water and confining pressure) that affect the strength of surrounding rocks. The second lining applied in time can effectively limit the further development of stress and deformation of initial support, and prevent the cracking and large deformation of concrete. Clearance convergence is suggested to be the main monitoring work in construction, because of its advantages of intuitive results, easy quality assurance of instrument installation and high accuracy.

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Study on failure mechanism of roadway with soft rock in deep coal mine and confined concrete support system

Cited by 156 publications

References 14 publications

Study on Deformation Mechanism and Support Measures of Soft Surrounding Rock in Muzhailing Deep Tunnel

Study on Deformation Mechanism and Support Measures of Soft Surrounding Rock in Muzhailing Deep Tunnel

Stress Field Distribution and Deformation Law of Large Deformation Tunnel Excavation in Soft Rock Mass

Physical and Mechanical Characteristics of Soft Rock Tunnel and the Effect of Excavation on Supporting Structure

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