高轴压比钢骨混凝土剪力墙抗震性能试验研究

为研究高轴压比钢骨混凝土剪力墙的抗震性能,完成了6片剪跨比为2.43、轴压比试验值为0.33~0.35的钢筋、钢骨和钢管混凝土剪力墙试件的往复水平力加载试验。试验表明:试件的纵筋和钢骨(钢管)受压屈服先于受拉屈服。试件的破坏形态为底部混凝土压碎剥落,约束边缘构件内的纵筋和钢骨(钢管)压曲,试件丧失竖向承载力。钢骨和钢管提高了试件的正截面承载力,且随位移增大试件能稳定地保持最大承载力。配置工字钢、槽钢和方钢管的试件的极限位移角为1/73~1/59,与钢筋混凝土试件基本相同;配置圆钢管的试件的极限位移角达1/44,墙端约束边缘构件配置圆钢管对提高高轴压比剪力墙的变形能力有显著作用。根据试验结果,提出了高轴压比钢骨混凝土剪力墙屈服、承载力极限状态和变形极限状态的截面应变、应力分布,建立了正截面承载力的计算式和顶点水平位移计算式,计算结果与试验结果符合较好。

Experimental study on seismic behavior of SRC shear walls with high axial force ratio

To study seismic behavior of shear walls with high axial force ratio,an experiment on six shear wall specimens subjected to cyclic lateral load was carried out.The shear span ratio of all specimens was 2.43 and the test axial force ratios were 0.33-0.35.The specimens included one reinforced concrete(RC) wall model,three steel reinforced concrete(SRC) wall models and two steel tube concrete(STC) wall models.The test results show that the compressive yielding of longitudinal reinforcements and structural steels(or steel tubes) of specimens occurred before their tensile yielding.The observed failure modes of the wall models included crash of concrete at the bottom of the specimens,buckling of the longitudinal reinforcements,the structural steels or steel tubes embedded in the boundary elements,loss of vertical load-carrying capacity.The strength of specimens was increased due to the use of structural steels and steel tubes in the boundary elements.With the increasing of displacement the maximum strength of the SRC walls and STC walls was stable.The ultimate drift ratio of specimens with structural steels or square steel tubes ranged 1/73 to 1/59,about the same with that of the RC wall specimen.While the ultimate drift ratio of the specimen with circular steel tubes was 1/44.It shows that the circular steel tubes embedded in the boundary elements obviously increase the deformation capacity of the shear wall with high axial force ratio.Based on the test results the strain distribution and the stress distribution along the section of high axial force ratio SRC walls at yield state,strength ultimate state and deformation ultimate state are proposed.The strength formula and the top lateral displacement formula are developed and compared well with the test results.