Because the confinement effect of the square steel tube was involved in the stress-strain relationship of the core concrete,this method could allow for the interaction between the steel tube and the concrete.

• 由于核芯混凝土的应力-应变模型包含了方钢管的约束作用；因此该方法体现了组合柱中钢与混凝土之间的相互影响.