Influence of Anchorage Arrangement on Uplift Resistance of Concrete Columns Reinforced by Circular Steel Tube with Ring Shear Connectors Using Taguchi Method

摘要

Using the Taguchi method, this study investigated several factors affecting the uplift resistance of the concrete columns reinforced by circular steel tube with ring shear connectors. Nine anchorage factors including steel tube cross section, concrete strength, cross section of concrete column, anchorage length of steel tube, longitudinal reinforcement ratio, transverse bar rate, center-to-center spacing of ring shear connectors, outstand width of ring shear connector, and distance of the first shear connector to the top plane of concrete column were considered for designing, each of which consisting of four levels. A total of 32 axial uplift load tests were conducted according to the L-32 orthogonal array proposed by the Taguchi method. The uplift load-displacement curve of the steel tubes can be simplified into three distinct regions: initial linear, curve transition, and final linear. The interpreted uplift resistances of elastic limit and failure threshold for each of the load tests were obtained. The analysis of mean and analysis of variance statistical approaches were used to evaluate the uplift load test results. The percentage contribution of each controllable factor was also determined. It revealed that the steel tube cross section showed a maximum influence on the interpreted uplift resistances of elastic limit and failure threshold with a contribution of 75.80 and 69.87%, respectively. Most interestingly, the anchorage length of steel tube and the layout of ring shear connectors had minor effects on the elastic limit and failure threshold of the uplift resistances.