The Thread-fixed One-side Bolt (TOB) is the bolt that can be installed from outside of a steel tube column, which is anchored by the threads on the bolt hole wall instead of the nuts. A series of tests were carried out to investigate the shear behavior of the lapped connection bolted by TOBs using both the steady state fire tests and the transient state fire tests. The two observed failure modes of TOB connected lapped connections were the bolt hole bearing failure (failure mode 1) and the bolt shank fracture (failure mode 2). The high temperature might cause the change of failure mode from failure mode 1 to failure mode 2. Lapped connections using Standard High Strength Bolt (SHSB) were also tested. The comparison results showed that the ultimate shear resistance of lapped connections using TOBs at different temperatures was about 90% of that using SHSBs with the same configuration at steady state fire test. Applicability of the design equations provided by Eurocode 3 was validated by the steady state fire test results. A Finite Element Model (FEM) was built and validated by the test results and the FEM was used to further study more derailed parameter studies including the influence of bolt strength, the bolt pretension force and the high temperature to the shear behavior of TOB connected lap connections.

螺纹固定单面螺栓（TOB）是一种可以从钢管柱外安装的螺栓，它是通过螺栓孔壁上的螺纹而不是螺母进行锚固的。使用稳态火灾试验和瞬态火灾试验进行了一系列试验，以研究由 TOB 螺栓连接的搭接连接的剪切行为。TOB 连接搭接连接的两种观察到的失效模式是螺栓孔轴承失效（失效模式 1）和螺栓柄断裂（失效模式 2）。高温可能导致失效模式从失效模式 1 变为失效模式 2。还测试了使用标准高强度螺栓 (SHSB) 的搭接连接。对比结果表明，在稳态燃烧试验中，使用TOBs的搭接连接在不同温度下的极限抗剪强度约为使用相同配置的SHSBs的90%。Eurocode 3 提供的设计方程的适用性通过稳态火灾测试结果得到验证。建立有限元模型 (FEM) 并通过测试结果进行验证，并利用 FEM 进一步研究更多脱轨参数研究，包括螺栓强度、螺栓预紧力和高温对 TOB 连接搭接剪切行为的影响连接。