钢管混凝土受压构件中钢管约束效能计算分析

Calculation Analysis for Steel Tube Restraint Efficiency of Compression Concrete-Filled Steel Tubular Members

摘要: 对于钢管混凝土结构中常见类型与规格的受压构件，其内填普通混凝土因成型与降温收缩而可能脱离钢管，即钢管与混凝土之间界面出现脱粘裂隙。此大概率现象使钢管约束混凝土的实际效能有所降低，使此类构件的组合截面始终协调变形的设计验算假定不一定或不完全符合实际情况，由此增大了钢管混凝土结构的空间动力特性计算的失真程度。基于解析钢管混凝土受压构件组合截面的各项变形，说明了钢管被动约束内填混凝土的基本条件，推导了关联钢管约束效能的轴压比限值与相关函数，并提出了可供相关规范修订及钢管混凝土结构设计与施工参考的实用技术建议。

Abstract: For common type and specification compression members in concrete-filled steel tubular structures, the filled ordinary concrete may be separated from the peripheral steel tube due to its forming and cooling shrinkage, i.e. the debonding crack may appear between the two. The greater probability phenomenon definitely reduces the practical constraint efficiency of the steel tube to the filled concrete, and makes the design check assumption that the composite section is always in line with the strip deformation uncertainly or incompletely in line to the actual situation, which may evidently increase the calculation deviation on spatial dynamic characteristics of concrete-filled steel tubular structures. Based on the analytical method, composite section deformations of concrete-filled steel tubular members in compression are analyzed, necessary conditions for the filled concrete confined by outer steel tube are explained, limit values of axial compression ratio and relative functions about the tube restraint efficiency are deduced, and then dependent practical suggestions are suggested which can be used as available reference for revision of relevant codes, design and construction of concrete-filled steel tubular structures.