钢管约束高强混凝土剪力墙抗震性能试验研究

Experimental study on the seismic behavior of steel tube confined high-strength concrete shear walls

高强混凝土剪力墙承载力高,刚度大,但变形能力较差。为改善此类构件的变形能力,在剪力墙边缘构件采用钢管约束形式代替普通箍筋,进行了钢管约束高强混凝土剪力墙低周反复加载试验,研究试件的破坏形态、破坏机理、延性、滞回特性、刚度退化及耗能性能。试验表明,通过约束边缘构件内设置钢管,试件水平承载力下降缓慢,在较大竖向压力作用下,试件仍可保持竖向承载能力,可明显提高高强混凝土剪力墙的变形能力;相同轴压比下,钢管约束高强混凝土剪力墙试件较普通配筋高强混凝土剪力墙试件,极限位移增大27%,耗能值增加81%。根据试验结果,建立了钢管约束高强混凝土剪力墙正截面承载力计算公式,建议在高强混凝土剪力墙底部加强区采取钢管约束构件的形式,以提高高强混凝土剪力墙抗震性能。

The high-strength concrete shear walls are characterized by the high bearing capacity and lower deformability.In order to improve their deformability,some specimens of high-strength concrete shear wall with the stirrup replaced by steel tube in the boundary members were fabricated,and then low-cycle repeated loading tests were conducted for the failure pattern,failure mechanism,deformability,hysteretic behavior,rigidity degeneration and energy dissipation capacity of the specimens,respectively. By providing confinement to the wall panel with steel tube,the horizontal bearing capacity of specimens declined slowly. Under high axial force,the vertical bearing capacity of specimens was stable,and their deformation and energy dissipation capacity were improved by the use of steel tubes in the boundary members. With the same axial compression ratio,the ultimate displacement and energy dissipation of steel-tube confined high-strength concrete shear walls may increase by 27% and 81%,respectively,compared with the ordinary reinforced high-strength concrete shear walls. Based on the results,the strength formula was developed. Furthermore,it is suggested that steel-tube members can be used in the strengthened portion at the bottom of shear walls.