耐候钢管混凝土柱局部轴向受压性能试验研究

研究目的:免涂耐候钢在桥梁中的应用越来越广泛,耐候钢管混凝土桥墩通常出现局部受压荷载工况。为研究矩形耐候钢管混凝土柱轴向局部受压特性,本文结合3根耐候钢管混凝土柱局部轴压试验,采用ABAQUS有限元软件进行模拟计算,结合试验和有限元方法分析局压面积比ψ2、含钢率、混凝土强度、钢管强度等参数对局压耐候钢管混凝土柱力学性能的影响。研究结论:(1)当含钢率小于0.14时,随着钢管厚度的增加,套箍效应对局压承载能力、刚度有很大的提高,当含钢率大于0.14时,继续增加钢管厚度对提高局压承载能力效果不明显,随着钢管厚度的增加,钢管混凝土界面的纵向剪力传递长度变长;(2)对参数进行回归分析发现:局压面积比ψ2、核心混凝土强度、含钢率是影响局压承载力的重要参数,钢材强度对局压承载能力影响较小;(3)提出了耐候钢管混凝土柱局压承载力简化计算公式;(4)本研究成果可为高架桥梁耐候钢管混凝土桥墩设计与应用提供技术支撑。

Experimental Research on the Local Axial Compression Performance of Concrete Filled Weathering Steel Tubular Stub Columns

Research purposes: The application of weathering steel without coating in bridge is more and more widely.The weather concrete-filled steel tube pier usually appears local compression load. In order to study the mechanical behavior of concrete-filled rectangular weathering steel tubular stub columns under the local axial compression,this paper carried out 3 concrete-filled weathering steel tubular stub columns experiments. The finite element( ABAQUS)method is used to analyze the concrete-filled weathering steel tubular stub columns. The influence of local compressive area ratio,steel ratio,concrete strength and weathering steel tube strength on axial local compressive performance of concrete-filled rectangular weathering steel tubular stub columns is evaluated by combining the experiment and finite element method.Research conclusions:( 1) When the steel rate is less than 0. 14,with the increase of the weathering steel tube thickness,the local pressure bearing capacity and stiffness have a great increase by the lateral confinement of weathering steel tubes. When the steel rate is greater than 0. 14,the continuous increase of the steel tube thickness has no obvious effect on the improvement of the local pressure bearing capacity. With the increase of steel tube thickness,the transfer length of longitudinal shear at concrete-filled steel tube interface becomes longer.( 2) The regression analysis of the parameters shows that local compressive area ratio,core concrete strength and steel ratio are important parameters affecting the local bearing capacity,while the steel strength has little influence on the local bearing capacity.( 3) The simplified formula for calculating the local bearing capacity of a short concrete filled weathering steel tubular column is presented.( 4) The research results can provide technical support for the design and application of concrete filled weathering steel tube piers of elevated bridges.