钢筋混凝土梁-方钢管混凝土柱环梁节点静力试验研究及设计方法

Experimental research on RC beam-STCC column joint connected with ring beam and design method

设计了11个RC梁-方钢管混凝土柱节点试件,考虑了节点形式、环梁截面尺寸、环梁纵筋和配箍率、抗剪环直径和数量及节点是否带楼板等因素,对其进行单调静力试验,研究梁柱节点受力性能及不同设计参数对其承载力的影响,分析试验现象及试件中钢筋应变发展规律。试验结果表明:环梁纵筋及箍筋的配筋率对RC梁-方钢管混凝土柱环梁节点的承载力具有显著的影响,可以通过调整环梁纵筋及配箍率使框架梁先于环梁破坏,达到强节点的目的;采用抗剪环筋传递剪力,能够可靠传力。在试验结果的基础上,以环梁破坏面的力平衡条件,推导了环梁节点承载力计算式,计算结果与试验结果吻合较好。

11 RC beam-square CFT column joint specimens were designed,considering the influences of joint form,ring beam dimension,ring beam reinforcement,diameter and number of shear rings and slab participation,etc.Monotonic static tests were carried out to investigate the macro mechanical behavior of the beam-column joints and the influences of various design parameters.The test observations and strain development in rebars were analyzed.The test results indicate： the longitudinal and transverse reinforcement of ring beam have significant influence on the load carrying capacity of the specimens.By changing adjusting the reinforcement ratios of the ring beam,the frame beams can be designed to fail prior to the failure of the ring beams to fulfill the strong joint requirement.Using ring reinforcement is convenient in terms of fabrication and construction and reasonable and reliable for the shear transfer.Based on the test results and the equilibrium of the surface forces of the ring beam at failure,the practical design method of the ring beam joint was derived.The calculation results agreed well with the test results.