轴向压力对配筋砌体短肢剪力墙抗剪性能的影响

Effect of Axial Pressure on Shear-resistant Performance of Reinforced Masonry Short-leg Shear Walls

通过对6片足尺290mm厚全灌芯配筋砌块砌体短肢剪力墙拟静力试验结果的分析,利用非线性有限元方法,模拟了此种墙体在压弯剪共同作用下的抗剪特性,研究了轴向压力对配筋砌块砌体短肢剪力墙抗剪性能的影响。研究表明,在不同高宽比的墙体中,轴向压力均对墙体的抗剪能力有较大影响,随着轴向压力增大,墙体抗剪能力先增大后减小(轴压比n从0.1增长到0.4时,墙体抗剪能力逐渐增大,而n从0.4增长到0.6时,墙体抗剪能力却逐渐减小);随着轴向压力的增大,墙体延性在逐渐减小。提出当轴压比等于0.3时,墙体抗剪能力和延性均较好,建议在建筑抗震设计规范中采用此值。

This paper intends to investigate the shear-resistant performance of reinforced concrete masonry （RCM） short-leg shear walls under the combined action of compression, bending and shear, and the effect of the applied axial pressure on the shear capacity of the walls was studied by non-linear finite element method based on tests of 6 full-scale fully grouted sample models subjected to low cyclic reversed lateral loads. It is concluded from the simulation results that there exists a positive correlation between the shear-resistant capacity of RCM short-leg shear walls and the magnitude of the applied axial load if the value of axial compression ratio is less than 0.4. However, when the axial compression ratio is from 0.4 to 0.6, a negative correlation is found. The wall-ductility decreases with increase of the applied axial pressure. It is suggested that if the axial compression ratio equals 0. 3, good shear-resistant performance and ductility can be achieved; thus, such value of 0. 3 is recommended to be adopted in codes for seismic design of buildings.