Open Access

ARTICLE

Analysis of the Stability and Mechanical Characteristics of the Jointed Surrounding Rock and Lining Structure of a Deeply Buried Hydraulic Tunnel

by Changchang Li¹, Zuguo Mo², Haibo Jiang^1,*, Fengchun Yang¹

1 College of Water and Architectural Engineering, Shihezi University, Shihezi, 832000, China
2 College of Water Resources and Hydropower, Sichuan University, Chengdu, 610065, China

* Corresponding Author: Haibo Jiang. Email:

Fluid Dynamics & Materials Processing 2022, 18(1), 29-39. https://doi.org/10.32604/fdmp.2022.017947

Received 18 June 2021; Accepted 11 September 2021; Issue published 10 November 2021

Abstract

On-site monitoring and numerical simulation have been combined to analyze the stability of the jointed surrounding rock and the stress inside the lining structure of a sample deeply buried hydraulic tunnel. We show that the deformation around the tunnel was mainly concentrated in the range 51.37 mm∼66.73 mm, the tunnel circumference was dominated by shear failure, and the maximum plastic zone was about 3.90 m. When the shotcrete treatment was performed immediately after the excavation, the deformation of the surrounding rock was reduced by 58.94%∼76.31%, and the extension of the plastic zone was relatively limited, thereby leading to improvements in terms of the stability of surrounding rock. When the support was provided at different time points, the stress of the surrounding rock in the shallow part of the tunnel was improved everywhere. In the tunnel section with high ground stress and joint development, when 10 cm steel fiber concrete spray layer and 40 cm C25 concrete secondary lining were used, the maximum tensile stress on the lining structure was 0.89 MPa, i.e., it was less than the tensile strength of concrete, which indicates that the internal force of the lining can meet the overall requirements.

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