T形RC剪力墙抗震变形指标限值试验

为研究T形钢筋混凝土(RC)剪力墙的抗震性能及其变形指标限值,根据中国现行规范要求,设计了12个不同剪跨比、设计轴压比及暗柱纵筋配筋率的T形RC剪力墙试件,通过低周往复试验对其破坏形态、滞回性能、耗能能力、变形能力进行研究.根据试验结果,提出基于骨架曲线和基于试验现象的划分方法,将12个试件划分为完好、轻微损坏、轻中等破坏、中等破坏、较严重破坏、严重破坏6个性能状态,并得到各试件不同性能状态对应的变形指标限值;同时结合收集的T形RC剪力墙试验结果进行回归分析,建立T形RC剪力墙不同性能状态下的变形指标限值与剪跨比、设计轴压比及暗柱纵筋配筋率之间的关系.结果表明:随着剪跨比的减小,试件的破坏形态由弯曲破坏转向弯剪破坏;基于骨架曲线的性能状态划分方法能建立起T形RC剪力墙变形指标限值与损伤程度的对应关系,具有合理性与适用性;其中T形RC剪力墙的变形指标限值与剪跨比、暗柱纵筋配筋率呈正相关性,与设计轴压比呈负相关性.

Experimental study on seismic deformation index limits of T-shaped RC shear walls

To investigate the seismic performance and deformation index limits, twelve T-shaped reinforced concrete (RC) shear walls with different shear span ratios, design axial compression ratios and longitudinal reinforcement ratios of boundary element were designed according to Chinese current codes. The specimens were tested under low frequency cyclic loading to study the seismic behaviors such as failure pattern, hysteretic characteristic, energy dissipation capacity and deformation capacity. According to the test results, corresponding deformation index limits of six performance states were obtained with two methods based on skeleton curve and experimental phenomena. Regression analysis was conducted with collected experimental results to build the correlations of deformation index limits at different performance states and shear span ratios, design axial compression ratios and longitudinal reinforcement ratios of boundary element. The results show that the failure patterns of specimens are transformed from flexural failure to flexural-shear failure with the decrease of shear span ratio. It is reasonable and feasible to establish the relationship between deformation index limits and damage extents of T-shaped RC shear walls based on skeleton curve. While the deformation index limit has positive correlations with shear span ratio and longitudinal reinforcement ratio of boundary element, there is a negative correlation between deformation index limit and design axial compression ratio.