Experimental study on performance of spring damping support structure system for large deformation tunnel in soft rock

Jinfeng Xu; Xiongyao Xie; Zhou Shi; Wuqiang Cai; Dinglun Xu; Chen Xu

Underground Space (Apr 2024)

Experimental study on performance of spring damping support structure system for large deformation tunnel in soft rock

Jinfeng Xu,
Xiongyao Xie,
Zhou Shi,
Wuqiang Cai,
Dinglun Xu,
Chen Xu

Affiliations

Jinfeng Xu: Department of Geotechnical Engineering, College of Civil Engineering, Tongji University, Shanghai 200092, China; Key Laboratory of Geotechnical and Underground Engineering, Ministry of Education, Tongji University, Shanghai 200092, China
Xiongyao Xie: Department of Geotechnical Engineering, College of Civil Engineering, Tongji University, Shanghai 200092, China; Key Laboratory of Geotechnical and Underground Engineering, Ministry of Education, Tongji University, Shanghai 200092, China; Corresponding author at: Department of Geotechnical Engineering, College of Civil Engineering, Tongji University, Shanghai 200092, China.
Zhou Shi: Department of Geotechnical Engineering, College of Civil Engineering, Tongji University, Shanghai 200092, China; Key Laboratory of Geotechnical and Underground Engineering, Ministry of Education, Tongji University, Shanghai 200092, China
Wuqiang Cai: Department of Geotechnical Engineering, College of Civil Engineering, Tongji University, Shanghai 200092, China; Key Laboratory of Geotechnical and Underground Engineering, Ministry of Education, Tongji University, Shanghai 200092, China
Dinglun Xu: Zhaotong City Zhaolu Expressway Investment and Development Co., Zhaotong, Yunnan Province 657000, China
Chen Xu: Institute of Rock Mechanics, Ningbo University, Ningbo, Zhejiang 315211, China

Journal volume & issue: Vol. 15
pp. 221 – 243

Abstract

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According to the convergence confinement theory, it is an effective measure to control the large deformation of high ground stress in fractured soft rock tunnels by using yielding support. The yielding support can be classified as either radial or circumferential yielding support. Circumferential yielding support is achieved by transforming radial displacement into circumferential tangential closure without compromising the support capacity of the primary lining support structure. Based on this, and inspired by the design principle of dampers, a yielding support structure system with spring damping elements as its core was developed, based on the connection characteristics of steel arches in highway tunnel, which can provide increasing support resistance in the yielding deformation section. Then the mechanical properties of spring damping elements were obtained through indoor axial pressure and flexural tests. In addition, according to these results with numerical calculations, the yielding support structure system with embedded spring damping elements can reduce the internal force of the support structure by approximately 10% and increase the area of the plastic zone of the surrounding rock by 11.23%, which can fully utilize the self-bearing capacity of surrounding rock and verify the effectiveness of circumferential yielding support. Finally, the spring damping support structure system was designed with reference to the construction process of the tunnel excavated by drilling and blasting method, and the transformation of the spring damping element to spring damping support structure was achieved. Based on field test results, surrounding ground pressure for the yielding support optimization scheme was reduced by 40% and more evenly distributed, resulting in the successful application and a reduction in the construction cost of large deformation tunnels in soft rock.

Published in Underground Space

ISSN: 2096-2754 (Print); 2467-9674 (Online)
Publisher: KeAi Communications Co., Ltd.
Country of publisher: China
LCC subjects: Technology: Engineering (General). Civil engineering (General): Engineering geology. Rock mechanics. Soil mechanics. Underground construction
Website: https://www.keaipublishing.com/en/journals/underground-space/

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