Socket connections with shear key interfaces have been widely used in precast building and bridge construction, of which the interfacial shear capacities become the main concern. Despite various previous studies, the force transfer mechanisms of shear key joints in socket connections have not been investigated thoroughly. In this paper, push-off tests were carried out on 16 specimens to investigate the interfacial shear behavior of such joints. Four failure modes were observed: post-pour concrete failure, shear key failure, splitting failure, and slip failure, among which splitting failure and slip failure should be avoided. Results showed that enhancing lateral constraint and post-pour strength, while reducing gap widths, significantly increased the shear capacity. Among different shear key configurations, the performance of joints with multiple small shear keys was the most satisfactory. According to the test results, the mechanical model for shear key joints in socket connections was proposed based on strut and shear friction theory. Distinct from previous models, the proposed model could cater to joints with moderate gap widths and constrained lateral dilatation, guiding the design of socket connections. Several design recommendations regarding the shear key dimensions, post-pour materials, and socket foundation configurations were proposed for engineering reference.

中文翻译：

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带剪切键承插连接界面剪切行为的实验和分析研究

带剪力键接口的承插连接已广泛应用于预制建筑和桥梁施工中，其中界面的抗剪能力成为人们关注的主要问题。尽管之前进行了各种研究，但承插连接中剪切键接头的力传递机制尚未得到彻底研究。本文对 16 个试件进行了推脱试验，以研究此类接头的界面剪切行为。观察到四种破坏模式：后浇混凝土破坏、剪键破坏、劈裂破坏和滑移破坏，其中应避免劈裂破坏和滑移破坏。结果表明，增强横向约束和后浇强度，同时减小间隙宽度，可显着提高抗剪能力。在不同的剪切键配置中，具有多个小剪切键的接头的性能是最令人满意的。根据试验结果，基于支柱和剪切摩擦理论，提出了承插连接剪力键接头的力学模型。与以前的模型不同，所提出的模型可以满足具有适度间隙宽度和受限横向膨胀的接头，指导承插连接的设计。提出了有关剪力键尺寸、后浇材料和承插基础配置的若干设计建议，以供工程参考。