钢管混凝土轴压构件徐变简化计算方法研究

Study on Simplified Creep Calculation Method of CFST Members under Axial Loading

为准确快速计算钢管混凝土轴压构件的长期变形,基于按照龄期调整的有效模量法和逐步积分法,提出了钢管混凝土轴压构件徐变的简化分析方法,对比分析了本文方法与传统方法的优缺点,探讨了混凝土徐变预测模型及其相对湿度取值对钢管混凝土轴压构件长期变形计算精度的影响,并与既有的试验结果进行对比分析。研究结果表明：本文简化分析方法简单且有较高精度,可以用于钢管混凝土轴压构件长期变形分析;采用相对湿度取值范围为90%-98%的CEB90模型和EC2模型,可以较为准确地分析钢管混凝土轴压构件长期变形。

In order to calculate long-term deformation of concrete-filled steel tube（ CFST） members properly and rapidly,based on the age adjusted effective modulus method and step-by-step integration method,a simplified analytical method to predict the creep of CFST under axial loading is proposed. The advantages and disadvantages of simplified and traditional methods are comparatively analyzed. The effect of creep prediction model of concrete and its relative humidity value on the calculation accuracy of long-term deformation of CFST axially compressed members are discussed,and the analytical result and test result are compared. The research result shows that（ 1） the simplified method is simple and has high accuracy,it could be used to analyze the long-term deformation of CFST axially compressed members;（ 2） using the CEB90 and EC2 creep models with relative humidity of 90% to 98%,the long-term behavior of the CFST members can be well predicted.