不同腔体构造圆钢管混凝土短柱抗震性能试验

为研究不同腔体构造对圆钢管混凝土短柱抗震性能的影响，进行了3个不同腔体构造的大截面尺寸圆钢管混凝土短柱试件的低周反复荷载试验。试件钢构件分别为圆钢管、圆钢管腔内焊接环向及竖向肋板并设置钢筋笼以及圆钢管内置圆钢管，其中后两者钢构件用钢量相等。各试件的轴力均相等。分析了各试件的承载力、刚度退化、滞回特性、延性、耗能及破坏特征。研究表明：竖向肋板的设置可以提高构件的受弯承载力；环向肋板可以显著约束钢管径向变形；内置圆钢管强化了核心区混凝土的约束，使得外钢管弹塑性变形能力增强；含钢率相等条件下，圆钢管内置圆钢管混凝土短柱与圆钢管腔内焊接环向及竖向肋板并设置钢筋笼混凝土短柱相比，虽然水平承载力略有下降，但是其延性系数和累积耗能能力有显著提高；3个不同腔体构造圆钢管混凝土短柱的等效黏滞阻尼系数分别为0.41、0.53、0.58，均具有较好的耗能性能。圆钢管混凝土柱在压、弯、剪复合受力状态下的承载力试验值高于按照我国规范和规程所得出的计算值，表明我国规范和规程在计算足尺试件承载力时，结果偏于安全。

Experiment on seismic behavior of circular concrete-filled steel tubular stub columns with different constructions

In order to investigate the influence of different construction exerting on seismic behavior of circular concrete-filled steel tubular (CFST) stub columns, low cyclic loading tests of three large-scale CFST stub columns with different constructions were conducted. The steel components of the specimen was set as steel tube, steel tube with welded horizontal rib, vertical rib and steel cage, and double-skin steel tube, respectively. The latter two specimens had the same amount of steel. The axial force of each specimen was equal. The bearing capacity, stiffness degradation, hysteretic behavior, ductility, energy dissipating capacity and failure characteristics of each specimen were analyzed. The tests results indicate that the setting of vertical ribs can improve the flexural bearing capacity of the member, the horizontal ribs have a significant confining effect on the radial deformation of the steel tube. Inner steel tube has strong confining effect on the core concrete, which enhances the plastic deforming capacity of the outer steel tube. Under the condition of having the same amount of steel, although the bearing capacity of double-skin steel tube is slightly lower than that of steel tube with welded horizontal rib, vertical rib and steel cage, the ductility coefficient and accumulated energy dissipating capacity are significantly improved. The equivalent viscous damping coefficients of each specimen with different constructions are 0.41, 0.53 and 0.58, possessing favorable energy dissipating performances. The test results of CFST column bearing capacity under combination effect of compression, bending and shear are higher than the calculated value according to Chinese code, indicating that the calculated bearing capacity of full-size specimens according to the Chinese code shows a tendency to be rather safe.