Compression-shear behavior of a scaled immersion joint with steel shear keys. (November 2017)

• Record Type: Journal Article
• Authors: Xiao, Wenhao; Yu, Haitao; Yuan, Yong; Taerwe, Luc; Xu, Guoping
• Is Part Of: Tunnelling and underground space technology. Volume 70(2017)
• Page Start: 76
• Page End: 88
• Publication Date: 2017-11
• Subjects: Immersed tunnel -- Immersion joint -- Steel shear-key -- Shear stiffness -- Shear capacity -- Shear failure; Tunneling -- Periodicals; Underground construction -- Periodicals; Tunnels -- Periodicals; Underground areas -- Periodicals; 624.193
• DOI: 10.1016/j.tust.2017.07.007
• Languages: English
• ISSNs: 0886-7798

Abstract

Highlights: Basic characteristics of an immersion joint with steel shear keys are observed. The hysteretic loop is found in shear force-displacement curve. The shear stiffness of the joint experiences a nonlinear decreasing trend. Not only shear keys but also rubber contribute to shear resistant of the joint. The failure mode of the joint is brittle shear failure of the shear keys. Abstract: The shear behavior of an immersion joint subjected to compressive-shear loads is investigated in this paper. To explore the performance of the immersion joint a scaled specimen, according to a specific protocol of a real project, is designed. A quasi-static shear force is applied horizontally while a constant compression force is maintained on the joint. A hysteresis effect is observed during the test and the area of the hysteretic loop increases with the shear force. An envelope curve of the shear force-displacement of the joint is obtained and divided into four stages based on the observed shear behavior of the joint. The shear stiffness of the immersion joint is calculated, showing a non-linear change with the shear displacement. The shear capacity of the model immersion joint and that of a single steel shear key are evaluated. It is found that the capacity of the joint is smaller than the sum of the capacities of all shear keys. This shows that the shear keys are not activated at the same time. The failure mode of the joint consists of a brittle shear failure in the single shear keys and a step-by-step failure way of the complete joint.