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Journal of Zhejiang University SCIENCE A
ISSN 1673-565X(Print), 1862-1775(Online), Monthly
2024 Vol.25 No.12 P.991-1005
Waterproofing performance of longitudinal segmental tunnel joints under external loads: a full-scale experimental investigation
Abstract: When subjected to external loads from the ground and nearby construction, tunnel segmental lining joints are prone to damaging deformation. This can result in water leakage into tunnels, posing great safety risks. With this issue in mind, we conducted a series of full-scale tests to study the effects of external loads on the waterproofing performance of longitudinal joints. A customized rig for testing segmental joints was developed to assess the effect of loading magnitude, eccentricity, and loading-unloading-reloading cycles on waterproofing performance. Additionally, the relationship between joint force, sealing gasket deformation, and waterproofing pressure was investigated. The results indicate that: (1) the sealing gasket’s compression rapidly decreases as external loads increase, which weakens the waterproofing capacity of the joint; (2) the watertightness limit dramatically decreases as the bending moment increases; (3) a loading-unloading-reloading cycle leads to degradation of the joint’s waterproofing performance. The findings of this study provide a reference for subsequent waterproofing design of segmental tunnel joints, helping ensure the safety of tunnels throughout their operational lifespans.
Key words: Segmental tunnel; Waterproofing performance; Full-scale experiment; Longitudinal joint
机构:1同济大学,岩土及地下工程教育部重点实验室,中国上海,200092;2同济大学,地下建筑与工程系,中国上海,200092;3中铁十四局集团大盾构工程有限公司,中国济南,250014
目的:城市盾构隧道在运营期间受外部环境扰动可能出现接缝张开、渗漏水等问题严重影响隧道安全。本文通过足尺试验的方法,研究外部荷载对纵向接缝防水性能的影响,为后续盾构隧道防水设计提供参考保障隧道安全运营。
创新点:1.设计了一种新型盾构隧道纵向接缝防水足尺试验设备;2.通过足尺试验,揭示了外荷载大小、偏心率和循环条件对盾构隧道纵向接缝防水性能的影响;3.根据试验结果及理论研究,研究了接头受力、密封垫片变形量和防水性能之间的相关性。
方法:1.针对盾构隧道纵向接缝进行三组足尺试验,揭示外荷载大小、偏心率和循环条件对盾构隧道纵向接缝防水性能的影响;2.通过理论研究,分析接头受力、密封垫片变形量和防水性能之间的相关性。
结论:1.外部荷载和弯矩的大小对纵向接缝的防水性能有很大影响,且接缝防水性能对外部荷载的改变很敏感。2.循环加载显著影响接缝的防水性能;在重新加载过程中,水密性极限仅为初始加载时的一半左右。3.在外部荷载作用下,隧道纵向接缝会产生旋转并张开。
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DOI:
10.1631/jzus.A2400354
CLC number:
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On-line Access:
2025-01-02
Received:
2024-07-11
Revision Accepted:
2024-09-27
Crosschecked:
2025-01-02