钢管混凝土墩柱截面选型

为了获得一种易于操作的钢管混凝土墩柱单肢截面优选方法,对工程中常见的3种截面形式(圆形、矩形与矩形中空夹层截面)进行了截面优选研究。基于统一理论和等效截面思想,提出了表征截面压弯承载力的经济性指标界限偏心率,研究了套箍系数、矩形截面高宽比、矩形中空夹层截面挖空率对界限偏心率以及3种钢管混凝土截面经济性的作用规律。结果表明:套箍系数、矩形截面高宽比、矩形中空夹层截面挖空率越大,矩形和矩形中空夹层截面的经济性越好; 当套箍系数大于0.8,矩形截面高宽比大于2.0,矩形中空夹层截面挖空率大于0.3时,这3个参数对界限偏心率的影响较小; 界限偏心率能够很好地表征钢管混凝土单肢截面的经济性; 在截面内力和材料给定的条件下,通过查界限偏心率表能够快速确定钢管混凝土墩柱最优截面形式,对工程实际具有一定的参考价值。

Cross Section Selection of Concrete-filled Steel Tube Pier Columns

In order to obtain an easy way to operate optimal selection method for single limb cross section of concrete-filled steel tube(CFST)pier column, the research of section optimization was carried out by the means of three common cross sections in engineering, including circular, rectangular and rectangular double-skin steel tubes. The economic index named boundary eccentricity ratio which could represent the cross section compressive bending capacity based on the unified theory and the method of equivalent cross section was presented. The effects of hoop coefficient, rectangular cross section aspect ratio, rectangular hollow section hollowed out rate on the boundary eccentricity ratio and the economy of the three CFST cross sections were studied. The results show that with the increasing of hoop coefficient, rectangular cross section aspect ratio and rectangular hollow section hollowed out rate, the economy of rectangular and rectangular double-skin steel tube cross section is getting better. When hoop coefficient is greater than 0.8, rectangular cross section aspect ratio is greater than 2.0 and rectangular hollow section hollowed out rate is greater than 0.3, the influences of the three parameters on boundary eccentricity ratio are small. The boundary eccentricity ratio can describe the economy of single limb cross section of CFST pier column preferably. The preferred cross-section of the CFST pier column can be obtained by searching the boundary eccentricity ratio table under the condition of given material and internal force. This method has certain reference value to the real project.