配筋空心方钢管高强混凝土构件的静力性能研究

Hollow concrete-filled square steel tube (H-CFST) is a common type of concrete-filled steel tube, its bearing capacity is smaller than concrete-filled square steel tube, and the application is limited. In order to improve the bearing capacity and ductility of (H-CFST), expand the application of hollow concrete-filled steel tube, a new type of composite column was proposed. The reinforced hollow-concrete-filled square steel tube (RH-CFST) is composed by precast prestressed high strength concrete tabular column, square steel tube and filled concrete between them. The RH-CFST column is reinforced with prestressed bars, deformed bars and spiral stirrup, which can improve the composite effect between steel tube and concrete, the performance of fire resistance and durability. The RH-CFST column has the advantages of high bearing capacity, high flexural stiffness, excellent seismic performance, simple structure of connection, convenient and fast construction. The project has a systematic research on mechanical behavior of RH-CFST columns by using experimental study, numerical simulation and theory analysis. The failure modes of RH-CFST columns and the cooperative work mechanism between different materials will be studied. The effect of slenderness on bearing capacity of long RH-CFST column is analyzed, and critical slenderness is determined. The flexural behavior and effect of eccentricity ratio on RH-CFST columns are studied, correction formulae between axial force and moment are built. At last, the practical design method for RH-CFST columns is given.

空心方钢管混凝土是常见的一种钢管混凝土结构形式，承载力与实心钢管混凝土相比偏低，限制了其在建筑工程中的应用，为提高空心方钢管混凝土柱的承载力和延性，拓展其应用范围，本项目提出一种由在工厂预制成型的预应力高强混凝土管柱与方钢管之间浇筑混凝土而形成的新型“配筋空心方钢管高强混凝土柱”。该新型组合柱内配置纵向预应力筋、普通钢筋和螺旋箍筋，可提高钢管和混凝土的组合效应、组合柱的抗火和耐久性能，具有承载力高、抗弯刚度大、抗震性能优良，节点构造简单、施工方便等优点。项目通过试验研究、数值分析和理论分析手段对配筋空心方钢管混凝土的受力性能进行深入研究。研究配筋空心方钢管高强混凝土柱的破坏模式和不同材料之间的协同工作机制；探讨长细比对组合柱承载的影响，确定界限长细比；研究组合柱的抗弯性能和偏心率对组合柱承载力的影响，并建立轴力-弯矩相关方程；最后，提出配筋空心方钢管高强混凝土柱实用设计方法。

为提高空心方钢管混凝土柱的承载力和延性，拓展其应用范围，本项目提出一种由在工厂预制成型的预应力高强混凝土管柱与方钢管之间浇筑混凝土而形成的新型“配筋空心方钢管高强混凝土柱”。本项目对配筋空心方钢管高强混凝土柱的静力性能进行了深入的研究，主要研究工作与成果包括：（1）进行了6个配筋空心方钢管高强混凝土轴压短柱试验研究，并结合ABAQUS有限元分析，得到了轴压短柱荷载-纵向应变曲线及轴压中长柱、长柱荷载-中截面侧向挠度曲线等；研究了配筋空心方钢管高强混凝土柱的破坏模式和不同材料之间的协同工作机制。（2）基于配筋空心方钢管高强混凝土轴压短柱试验和精细化有限元分析，给出组合材料的本构关系。在参数分析的基础上，定义了轴压中长柱、长柱的界限长细比，得出配筋空心方钢管高强混凝土轴压短柱、中长柱与长柱承载力计算方法与实用设计方法。（3）进行了6个配筋空心方钢管高强混凝土纯弯构件的试验研究，得到了弯矩-挠度曲线等；建立了基于钢管混凝土统一理论的配筋方空心钢管高强混凝土纯弯构件的截面抗弯模量和塑性发展系数。（4）在现有承载力公式的基础上，通过对试验和有限元结果进行拟合，推导出配筋空心方钢管高强混凝土纯弯构件承载力计算公式。（5）进行了7个配筋空心方钢管高强混凝土偏压构件试验研究和有限元分析，进行不同影响因素的偏压构件的受力全过程分析，研究了其工作机理和破坏形态。（6）采用钢管混凝土统一理论和经验系数法推导出了偏压短柱承载力相关方程，推导出偏压构件的承载力计算公式。