双向螺旋箍筋约束高强蜂窝型钢-UHPC短柱轴压性能研究  

Study on axial compressive behavior of high strength cellular steel UHPC short column with bi-directional spiral stirrups

作　　者：徐龙康 杨勇[1,2] 张明俊 张扬 XU Longkang;YANG Yong;ZHANG Mingjun;ZHANG Yang(College of Civil Engineering,Xi'an University of Architecture&Technology,Xi'an 710055,China;Key Lab of Structural Engineering and Earthquake Resistance,Ministry of Education(XAUAT),Xi'an 710055,China)

机构地区：[1]西安建筑科技大学土木工程学院,陕西西安710055 [2]西安建筑科技大学结构工程与抗震教育部重点实验室,陕西西安710055

出　　处：《建筑结构学报》2025年第1期147-159,共13页Journal of Building Structures

基　　金：国家自然科学基金项目(51978565);陕西省重点科技创新团队项目(2024-01-01)。

摘　　要：为研究双向螺旋箍筋约束高强蜂窝型钢-UHPC短柱(简称“CS-UHPC”)的轴压性能,揭示箍筋直径、箍筋间距和型钢扩张比等设计参数对该类柱轴压性能的影响,设计并完成了8根轴心受压短柱试验。通过短柱的破坏形态、承载力、荷载-位移曲线、变形能力、刚度、荷载-应变曲线等分析双向高强螺旋箍筋和蜂窝型钢对该类柱的约束增强机理和失效性态。同时,将短柱截面划分为不同的UHPC约束区,计算双向高强螺旋箍筋的有效约束,并将蜂窝型钢等效为两个T形钢分肢的缀板式格构柱,提出CS-UHPC短柱的轴压承载力计算方法。研究结果表明:所有CS-UHPC短柱均发生典型的轴压破坏,由于双向高强螺旋箍筋的约束作用,裂缝发展缓慢,荷载-位移曲线下降段趋于平缓,并维持较高的残余承载力水平,与传统矩形箍筋短柱相比,双向高强螺旋箍筋短柱的轴压承载力增加13.4%、变形系数提高209%、刚度提高11.1%;与实腹短柱相比,扩张比为1.3和1.5的蜂窝腹板短柱的轴压承载力分别增加14.0%和3.8%,变形系数分别提高46.6%和34.4%,刚度分别提高32.3%和23.3%;当双向高强螺旋箍筋直径从4 mm增加至6 mm和8 mm,短柱轴压承载力分别增加17.5%和30.7%,变形系数分别提高15.7%和21.6%,刚度分别提高11.3%和18.6%;当双向高强螺旋箍筋间距从50 mm增加至80 mm和110 mm,短柱轴压承载力分别减少16.0%和14.0%,变形系数分别降低1.8%和17.2%,刚度分别降低14.8%和6.1%。To investigate the axial compression behavior of high-strength cellular steel UHPC short columns confined with bi-directional spiral stirrups(CS-UHPC) and to clarify the influence of design parameters, including stirrup diameter, stirrup spacing and steel expansion ratio, on the axial compression performance of short column, eight short column uniaxial compression tests were designed and completed. The investigation into the confinement enhancement mechanism and failure modes of CS-UHPC short columns involved observing failure patterns and analyzing parameters such as bearing capacity, load-displacement curve, deformation capacity, stiffness, loadstrain curve, and damage evolution. Meanwhile, the section of short column was divided into separate UHPC confinement regions to calculate the effective confinement provided by the bi-directional high-strength spiral stirrups. The cellular steel is treated as two T-stub steel divided lattice columns with batten plate. A method for calculating the axial compressive capacity of CS-UHPC short column was proposed. The results indicate that short column exhibits typical axial compression damage. The CS-UHPC short column experiences slow axial compressive failure process due to the combined confinement effect of bi-directional high-strength spiral stirrups and highstrength cellular steel. The descending section of load-displacement curve exhibits smooth and maintains a relatively high residual axial compressive capacity. Compared to short columns with conventional rectangular stirrups, the short column with bi-directional high-strength spiral stirrups shows an increase in compressive bearing capacity by 13. 4%, deformation coefficient by 209% and stiffness by 11. 1%. In comparison to short columns with solid web, cellular web short columns with expansionratios of 1. 3 and 1. 5 shows an increase in compressive bearing capacity by 14. 0% and 3. 8%, deformation coefficient by 46. 6% and 34. 4%, and stiffness by 32. 3% and 23. 3%, respectively. When the diameter of the bidirection

关 键 词：高强蜂窝型钢-UHPC短柱 双向螺旋箍筋 轴压试验 轴压性能 约束机理 

分 类 号：TU375.4[建筑科学—结构工程] TU317.1