Route selection of deep-lying and hard rock tunnel in the Sichuan-Tibet Railway based on rock burst risk assessment

Shikuo CHEN; Hanrui LI; Hang ZHOU; Xingqiang CHEN; Tong LIU

doi:10.16030/j.cnki.issn.1000-3665.202103099

Shuiwen dizhi gongcheng dizhi (Sep 2021)

Route selection of deep-lying and hard rock tunnel in the Sichuan-Tibet Railway based on rock burst risk assessment

Shikuo CHEN,
Hanrui LI,
Hang ZHOU,
Xingqiang CHEN,
Tong LIU

Affiliations

Shikuo CHEN: Department of Geological Engineering, Southwest Jiaotong University, Chengdu, Sichuan　611756, China
Hanrui LI: Department of Geological Engineering, Southwest Jiaotong University, Chengdu, Sichuan　611756, China
Hang ZHOU: Department of Geological Engineering, Southwest Jiaotong University, Chengdu, Sichuan　611756, China
Xingqiang CHEN: China Railway First Survey and Design Institute Group Co. Ltd., Xi’an, Shaanxi　710043, China
Tong LIU: Department of Geological Engineering, Southwest Jiaotong University, Chengdu, Sichuan　611756, China

DOI: https://doi.org/10.16030/j.cnki.issn.1000-3665.202103099
Journal volume & issue: Vol. 48, no. 5
pp. 81 – 90

Abstract

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The large terrain undulations and strong regional geological structures are the typical characteristics along the Sichuan-Tibet Railway. The high ground stress problem in tunnel construction is extremely complex, especially the rockburst problem in deep-lying and hard rock tunnels, which restricts route selection schemes and becomes a major difficult problem of construction. Because of the complex geological conditions of the tunnel engineering, the evaluation results often deviate from the actual situation if the rockburst evaluation index is not pertinent. The key factors of rockburst is considering comprehensively, and five factors are selected as the evaluation indexes, including the ratio of the uniaxial compressive strength of rock to the maximum main stress of the surrounding cave wall, the ratio of the maximum tangential stress of the surrounding cave wall to the uniaxial compressive strength of rock, the ratio of compressive to the tensile strength of rock, the elastic strain energy index, and the intactness index of rock mass. The entropy weight method is used to determine the weight of each index, and a rock burst risk assessment model is constructed based on the basic theory and calculation rules of the ideal point method. By calculating the distance between each mileage section and the ideal point, a comprehensive comparison of rock burst risk assessment is carried out on three route plans of a tunnel on the Sichuan-Tibet Railway. The results show that the total rock burst sections of route B is 24.9%, and the uncontrollable rock burst sections account for 13.4%. The route B is about 4% lower than the other two alternative schemes. The route B is determined as the optimal plan according to the impact of rock burst disasters. This method can provide a new scientific basis and technical support for the comprehensive geological selection of deep-lying and hard rock tunnels.

Published in Shuiwen dizhi gongcheng dizhi

ISSN: 1000-3665 (Print)
Publisher: Editorial Office of Hydrogeology & Engineering Geology
Country of publisher: China
LCC subjects: Science: Geology
Website: https://www.swdzgcdz.com/indexen.htm

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