型钢超高强混凝土柱截面曲率延性研究  

Curvature ductility of steel-reinforced ultra-high-strength concrete column sections

作　　者：贾金青[1] 朱伟庆[1] 余芳[1] 张丽华[1] 

机构地区：[1]大连理工大学海岸与近海工程国家重点实验室,辽宁大连116024

出　　处：《土木工程学报》2013年第1期42-51,共10页China Civil Engineering Journal

基　　金：国家自然科学基金(50878037;51078059;51178078)

摘　　要：采用截面纤维单元分析法,编制了截面弯矩-曲率全过程分析程序。选取相关试验对该分析方法和计算程序进行验证,结果表明计算结果与试验结果吻合较好,此分析方法及计算程序可以较好地预测柱正截面强度和截面曲率延性。运用该分析方法与计算程序研究了轴压力系数、混凝土强度、配箍以及型钢对型钢超高强混凝土柱截面曲率延性μφ的影响。结果表明:轴压力系数对截面曲率延性的影响最为显著;增强配箍能有效提高截面曲率延性,且改善配箍形式比仅提高体积配箍率更为有效;承受相同较大的轴向压力时,具有相同抗弯承载能力的型钢混凝土柱截面的曲率延性好于钢筋混凝土柱截面;箍筋有效约束指标Ie'能综合反映配箍形式、箍筋直径、间距以及强度对截面曲率延性的影响,在其他条件相同时,μφ与Ie'基本成正比。建议选取n=0.65作为抗震等级为二级时C100～C110级型钢超高强混凝土框架柱的轴压力系数限值,并提出了此时满足截面不同曲率延性需求的最小配箍计算公式。A program was developed to analyze the moment-curvature behavior of steel-reintbrced concrete column sections based on the fiber element method. The program was compared and validated with selected experimental results, and the predicted values were in good agreement with the experimental results, indicating that the analysis method and the program could predict the strength and curvature ductility correctly. Based on this method and the program, a parametric study was conducted to investigate the effects of various factors on curvature ductility of steel-reinforced ultra- high-strength concrete column sections. The results show that axial pressure coefficient has the most obvious influence on the curvature ductility. Enhancing the confinement of stirrups leads to an increase in ductility, and improving stirrup form is more effective than solely increasing stirrup ratio. Under the same large axial compressive force and with the same moment capacity, a steel-reinforced section shows higher ductility than a reinforced concrete section. Under the same conditions, curvature ductility of composite sections is proportional to the effective eomqnement index Ie＇ . Finally, the limited axial pressure coefficient is suggested and a design formula is developed for stirrup confinement of composite sections under the limited axial pressure with different ductility demands.

关 键 词：型钢超高强混凝土柱 截面纤维单元分析法 截面曲率延性 延性系数 

分 类 号：TU528.31[建筑科学—建筑技术科学] TU375.3