长期荷载作用对钢管混凝土核心柱承载力影响的数值分析

Numerical Analysis of the Influence of Long-term Loads on Bearing Capacity of CCRST

本文引入了考虑长期荷载作用效应影响的混凝土应力应变关系模型,该模型是综合考虑了徐变、收缩以及长期荷载的应力水平等因素,通过对短期荷载作用下的混凝土本构模型进行修正得到的。利用该模型,对钢管混凝土核心柱(即在普通的钢筋混凝土柱截面的核心增设一钢管的柱型)的轴力-弯矩相关曲线进行了数值分析,考察了长期荷载作用对该类柱承载力的影响。分析结果表明,考虑长期荷载作用的影响,柱子的承载力有所降低。

A concrete stress-strain models under long-term loads is introduced by modifying the short-term concrete model to incorporate effects of creep, shrinkage and also long-term stress level for concrete in compression. The proposed model was used in the numerical analysis of load-moment interaction relationships of the concrete columns reinforced with concrete filled steel tube （CCRST）, which is an ordinary reinforced-concrete column where there is a steel tube designed to be put in the core additionally, to investigate the influence of long-term loads on the bearing capacity of the columns. Analysis results indicate that there is a noticeable reduction in bearing capacity of the columns when the effect of long-term loads being took into account.