钢筋混凝土剪力墙拉压变轴力低周往复受剪试验研究  

Low-cyclic repeated shear test on tension-compression variable axial force of reinforced concrete shear wall

作　　者：任重翠[1] 肖从真[1] 徐培福[1] 陈涛[1] Ren Chongcui;Xiao Congzhen;Xu Peifu;Chen Tao(China Academy of Building Research, Beijing 100013, China)

机构地区：[1]中国建筑科学研究院,北京100013

出　　处：《土木工程学报》2018年第5期16-25,共10页China Civil Engineering Journal

基　　金：国家自然科学基金(51578522)

摘　　要：完成了截面纵筋率为3%,剪跨比为1.5的2片钢筋混凝土剪力墙拉压变轴力低周往复受剪试验。当剪力墙反复处于拉剪、压剪受力状态时,剪力墙在拉剪阶段屈服,在压剪阶段发生脆性受压破坏。当承受的拉力较小时剪力墙为大偏心受拉,斜裂缝处竖向和水平分布筋屈服;当承受的拉力较大时剪力墙为小偏心受拉,水平通缝处截面纵筋屈服。剪力墙受压时刚度大,端部纵筋受拉后再受压容易屈曲,因此其抗压剪承载力先于抗拉剪承载力达到峰值,抗压剪承载力因混凝土的受压脆性经过峰值点后迅速下降。与拉剪受力相比,剪力墙在压剪受力时的承载力高、变形小。剪力墙的抗拉剪、抗压剪承载力和抗压剪变形能力随目标轴力幅度的提高而下降。与定轴力受剪试验结果相比,剪力墙在拉压变轴力受剪时的抗拉剪承载力降低,抗压剪承载力未有显著变化。轴拉力不仅会降低剪力墙的抗剪承载力,还会加大剪力墙受拉、受压时抗剪承载力的差异,因此应控制底部剪力墙受拉,并控制墙体受拉水平。Low-cyclic repeated shear tests of tension-compression variable axial force were carried out on two specimens of shear wall with sectional longitudinal reinforcement ratio of 3% and shear-span ratio of 1.5. When shear wall repeatedly switched between tension-shear state and compression-shear state, yielding occurred in the tension-shear stage and fragile failure occurred in the compression-shear stage. When the tensile force was small, shear wall subjected to the tension state of large eccentricity, the horizontally and vertically distributed steel bars at diagonal cracks yielded; when the tensile force was large, shear wall subjected to the tension state of small eccentricity, and the longitudinal steel bars at the horizontal ：atoning-through cracks yielded. The stiffness of shear wall appeared to be large in the compression-shear state, and the longitudinal steel bars at the end easily yielded after experiencing the tensile force followed by the compressive force. Hence, the compression-shear capacity may reach the peak value before the tension-shear capacity. The compression-shear capacity of shear wall dropped rapidly after the peak value due to the compressive brittleness of concrete. Compared with the tension-shear state, the bearing capacity of shear wall in the compression-shear state was larger, and the deformation was smaller. The tension-shear capacity, compression-shear capacity and compression-shear deformation capacity of shear wall decreased with the increase of target axial force amplitude. Compared with shear test results of fixed axial force, the tension-shear capacity of shear wall under the shearing of tension-compression variable axial force was reduced, and the compression-shear capacity was not changed significantly. Axial force would not only reduce the shear capacity of shear wall, but also increase the difference of shear capacity of shear wall in the tension state and in the compression state, and hence, the bottom shear wall shall be controlled to be in tension and the tension level

关 键 词：钢筋混凝土剪力墙 拉压变轴力低周往复受剪试验 受压破坏 抗剪承载力 

分 类 号：TU375.402[建筑科学—结构工程]