带圆钢管的劲性高强混凝土轴压短柱的承载力及可靠度分析

Ultimate Strength of High Strength Concrete Columns Reinforced with Concrete Filled Steel Tube Under Axial Compression and their Reliability Analysis

为了探求一个合理的设计公式来计算带圆钢管的劲性高强混凝土柱在轴压下的极限强度,完成了包含13个短柱试件在内的轴心受压试验以研究该类柱在轴压下的破坏模式和极限强度.试验结果表明,在荷载作用下,直到荷载接近极限值时,柱中钢管、纵向钢筋以及混凝土三者之间的纵向应变基本上是协调的,计算结果与试验结果吻合良好,因此可以采用叠加原理来计算带圆钢管的劲性高强混凝土柱在轴压下的极限承载力.此外,分析了该极限承载力计算公式的可靠度水平.分析结果表明,该承载力计算满足GB50068-2001对构件可靠指标的要求.

This paper aims at developing a rational design formula to predict the ultimate strength of high strength concrete columns reinforced with concrete filled steel tube （HSCCRST） under axial compression. In order to investigate the failure mode and the ultimate strength of the columns under axial compression, experimental tests of 13 specimens under axial compression were performed. Test results showed that the longitudinal strain of the steel tube, the longitudinal reinforcement, and the concrete in the column were all compatible under loading until the load applied was close to the ultimate load. Therefore, the ultimate strength of HSCCRST could be calculated in the principle of superposition. In addition, the reliability level of the columns under axialcompression designed following the proposed formula was investigated Analysis results indicated that the reliability indexes of the columns designed following the proposed formula satisfied the demand of Unified Standard for Reliability Design of Building Structures （GB 50068-2001）, National Standard of the People＇s Republic of China.