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Study on the Mechanical Response of Tunnel Segment Structures in Ultra-large Diameter Shallow-buried Shield Tunnels during Construction
(1. Hangzhou Fuyang Urban Construction Investment Group Co., Ltd., Hangzhou 311400; 2. China Railway Siyuan Survey and Design Institute Group Co., Ltd., Wuhan 430063; 3. College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310058)
Abstract To explore the mechanical response of tunnel segment structures under complex loads during the con? struction of ultra-large diameter shallow-buried shield tunnels, this study uses the Qinwang River-crossing project as the engineering background. A three-dimensional refined calculation model was established considering the construction load combinations and boundary conditions. The model was used to analyze and compare the longitudinal uplift, circumferential misalignment, lateral deformation, longitudinal internal forces, and damage conditions of the tunnel segments under different grouting pressure and grout setting time conditions. The results show that: (1) The uplift of both the crown and the invert arch of the tunnel segment lining ring increases with the increase in grouting pressure and the extension of the grout setting time, with the grout setting time having a more significant impact on the uplift. (2) The misalignment of the segment can be divided into the upper misalignment section, transition section, lower misalignment section, and the stable section. The maximum misalignment occurs at the junction between the segments in shield shell section and in the fluid grout section, and between the segments in the fluid grout section and in the set grout section. (3) Compared to the segments in the fluid grout section, the segments in the shield shell section and the front half of segments in the set gout section are more prone to lateral deformation, which increases with the grouting pressure. (4) The tensile damage in the segments concentrates on the outer spandrel of segments in the fluid grout section and at 45° below the inner waist of the tunnel.
Abstract：
To explore the mechanical response of tunnel segment structures under complex loads during the con? struction of ultra-large diameter shallow-buried shield tunnels, this study uses the Qinwang River-crossing project as the engineering background. A three-dimensional refined calculation model was established considering the construction load combinations and boundary conditions. The model was used to analyze and compare the longitudinal uplift, circumferential misalignment, lateral deformation, longitudinal internal forces, and damage conditions of the tunnel segments under different grouting pressure and grout setting time conditions. The results show that: (1) The uplift of both the crown and the invert arch of the tunnel segment lining ring increases with the increase in grouting pressure and the extension of the grout setting time, with the grout setting time having a more significant impact on the uplift. (2) The misalignment of the segment can be divided into the upper misalignment section, transition section, lower misalignment section, and the stable section. The maximum misalignment occurs at the junction between the segments in shield shell section and in the fluid grout section, and between the segments in the fluid grout section and in the set grout section. (3) Compared to the segments in the fluid grout section, the segments in the shield shell section and the front half of segments in the set gout section are more prone to lateral deformation, which increases with the grouting pressure. (4) The tensile damage in the segments concentrates on the outer spandrel of segments in the fluid grout section and at 45° below the inner waist of the tunnel.
WAN Dongxing1 ZHANG Di2 SUN Feng2 PAN Chenxin3 ZHU Zhenwei1 XU Xiaofeng1 HE Chao1 SHEN Tuqi1
.Study on the Mechanical Response of Tunnel Segment Structures in Ultra-large Diameter Shallow-buried Shield Tunnels during Construction[J] MODERN TUNNELLING TECHNOLOGY, 2025,V62(1): 135-146
2025, Vol. 62 