ZHANG J F, LIU Y L, SHEN W M,et al.Field experimental study on the mechanical behavior of segmental linings in small-radius curved shield tunnels[J].Journal of Henan Polytechnic University(Natural Science) ,2026,45(4):67-76.

doi:10.16186/j.cnki.1673-9787.2025120029

Received:2025/12/10

Revised:2026/04/17

Published:2026/06/17

Field experimental study on the mechanical behavior of segmental linings in small-radius curved shield tunnels

Zhang Jianfeng1, Liu Yongli2, Shen Wenming1, Wu Wenbing3, Dai Zhihao4,5, Yang Guolin5

1.China Railway Eryuan East China Survey and Design Co.， Ltd.， Hangzhou  310043， Zhejiang， China;2.School of Civil Engineering， Architecture and Environment， Hubei University of Technology， Wuhan  430068， Hubei， China;3.Faculty of Engineering， China University of Geosciences， Wuhan  430074， Hubei， China;4.School of Infrastructure Engineering， Nanchang University， Nanchang  330031， Jiangxi， China;5.School of Civil Engineering， Central South University， Changsha  410075， Hunan， China

Abstract: Objectives To investigate the mechanical behavior of segmental linings in small-radius curved shield tunnels during construction， field tests and theoretical analyses were conducted to study the evolution of surrounding rock pressure and segment internal forces under different curvature radii.  Methods Straight sections and curved sections with radii of 150 m and 300 m in the S-shaped section of the Wanjiali Road power tunnel in Changsha， Hunan Province， were selected as test sections. Earth pressure cells and reinforcement stress gauges were embedded at key positions of the segments for continuous monitoring. Meanwhile， the homogeneous ring method and the beam-spring method were employed to calculate the internal forces of the linings， and the calculated results were compared with field measurements. Results The results indicate that the mechanical behavior of segmental linings during construction is significantly influenced by the curvature radius. Compared with straight sections， curved sections require a larger number of shield advance rings for the surrounding rock pressure and segment internal forces to reach stable states， and the stabilization duration increases as the curvature radius decreases. The distributions of surrounding rock pressure and lining internal forces in curved sections exhibit pronounced asymmetry between the inner and outer sides. In the curved section with a radius of 300 m， the surrounding rock pressure on the inner side is generally higher than that on the outer side. Field measurements further show that the bending moments of segments in the lower part of the tunnel are generally larger than those predicted by the homogeneous ring method and the beam-spring method， and this discrepancy becomes more significant in the curved section with a radius of 150 m.  Conclusions During the construction of shield tunnels on small-radius curves， a significant curve effect exists， making the lining structure on the inner side of the curved section more prone to unfavorable stress conditions. Design analysis and construction control parameters need to be optimized in conjunction with field monitoring results obtained during the construction period.

Key words:shield tunnel;small radius curve;segment lining;field test