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

Zhang, Heng; Chen, Liang; Zhu, Yimo; Zhou, Zelin; Chen, Shougen

doi:10.3390/app9050865

Cited by 37 publications

(23 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Based on the same engineering background, we have studied large deformation of soft rock tunnel by theoretical analysis and numerical simulation in our published papers and expressed corresponding views, such as stress field distribution and deformation law [44]. In this paper, based on the further analysis of monitoring data, new progress has been made.…”

Section: Discussionmentioning

confidence: 99%

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

et al. 2019

Self Cite

View full text Add to dashboard Cite

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.

show abstract

Section: Discussionmentioning

confidence: 99%

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

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…Jiang et al studied the influence of the engineering mechanical properties of the soft rock on the loose pressure of the surrounding rock and put forward the theory of predicting the loose pressure of the surrounding rock and the development trend of the plastic zone of the soft rock [16]. Zhang et al studied the stress field distribution and deformation law during the excavation of soft rock large deformation tunnels through theoretical analysis, numerical simulation, and field monitoring [17].…”

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

View full text Add to dashboard Cite

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.

show abstract

“…Recently, more and more underground engineering with characteristics of long and deep burial will be built in deep, soft surrounding rock areas [1][2][3][4][5][6]. In situ stress measurement in these areas is essential to determine the mechanical properties of fractured rock masses, analyze the stability of underground structures (e.g., tunnels, caverns, shafts, and other openings), and design the rock support system [7][8][9].…”

Section: Introductionmentioning

confidence: 99%

A Novel in Situ Stress Monitoring Technique for Fracture Rock Mass and Its Application in Deep Coal Mines

et al. 2019

View full text Add to dashboard Cite

A novel in situ stress monitoring method, based on rheological stress recovery (RSR) theory, was proposed to monitor the stress of rock mass in deep underground engineering. The RSR theory indicates that the tiny hole in the rock can close gradually after it was drilled due to the rheology characteristic, during which process the stress that existed in the rock can be monitored in real-time. Then, a three-dimensional stress monitoring sensor, based on the vibrating wire technique, was developed for in field measurement. Furthermore, the in-field monitoring procedures for the proposed technique are introduced, including hole drilling, sensor installation, grouting, and data acquisition. Finally, two in situ tests were carried out on deep roadways at the Pingdingshan (PDS) No. 1 and No. 11 coal mines to verify the feasibility and reliability of the proposed technique. The relationship between the recovery stress and the time for the six sensor faces are discussed and the final stable values are calculated. The in situ stress components of rock masses under geodetic coordinates were calculated via the coordinate transformation equation and the results are consistent with the in situ stress data by different methods, which verified the effectiveness of the proposed method.

show abstract

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

Cited by 37 publications

References 33 publications

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

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

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

A Novel in Situ Stress Monitoring Technique for Fracture Rock Mass and Its Application in Deep Coal Mines

Contact Info

Product

Resources

About