高轴压比作用下型钢超高强混凝土框架抗震试验研究

为了研究型钢超高强混凝土框架结构的抗震性能,进行了3榀单层单跨框架结构拟静力试验分析,研究了框架结构在低周反复荷载作用下结构整体的破坏形式和柱根部的破坏过程,并由此分析了与其相对应的滞回曲线和骨架曲线,梁端和柱底的应变,以及各阶段的荷载值和位移值,并通过应变情况判别整体结构的变形情况.通过实验得到框架结构的延性系数、耗能能力、强度退化和刚度退化.结果表明,型钢超高强混凝土框架具有良好的延性,正向和反向的延性系数相差不大,耗能能力良好,强度和刚度退化比较缓慢,滞回曲线饱满;柱子是框架结构消耗地震能量的主要组成部分,而梁的约束也提高了结构的整体性和耗能能力,使结构在承载力下降到极限荷载的80%之后,仍能保持结构整体的稳定性,同时具有一定的耗能能力,保证了结构在大震作用下,仍拥有一定的承载能力,不至瞬间倒塌.

Study of Seismic Performance of Steel Ultra High Strength Concrete Frames Under the Effect of High Axial Compression Ratio

In order to study the seismic performance of steel reinforced ultra-high strength concrete frame structure, three quasi-static cyclic tests of steel reinforced super-high strength concrete frames with one-story and one-bay were carried out. The global failure modes as well as the local failure at the bottom column-end under low-cycle reversed load were examined. The hysteretic and skeleton curves were analyzed, and the strain of the beam end and column bottom was evaluated. Meanwhile, the loading and displacement values at different stages were evaluated, and the global deformation of the entire structure was further understood through the development of local strains. Furthermore, the strength, ductility, and energy-dissipation capacity of the frame structures were obtained through the tests. The test results show that the steel reinforced ultra-high strength concrete frames exhibit good ductility and energy dissipation capacity, showing little discrepancy between forward reverse ductility coefficient, slow degradation of strength and stiffness, and plump hysteretic curve. It is also concluded that most of the earthquake energy is dissipated in columns, while the constraint effect of beams improves the global stability of frame structure as well as energy dissipation capability especially after the load-carrying capacity decreases to 80 percent of the ultimate load, which provides the effective load-carrying capacity in structures under severe earthquakes, and thus sudden collapse of the frame structure can be avoided.