纪晓东, 程小卫, 徐梦超. 小剪跨比钢筋混凝土墙拉剪性能试验研究[J]. 工程力学, 2018, 35(S1): 53-61. DOI: 10.6052/j.issn.1000-4750.2017.06.S004
引用本文: 纪晓东, 程小卫, 徐梦超. 小剪跨比钢筋混凝土墙拉剪性能试验研究[J]. 工程力学, 2018, 35(S1): 53-61. DOI: 10.6052/j.issn.1000-4750.2017.06.S004
JI Xiao-dong, CHENG Xiao-wei, XU Meng-chao. Experimental study on tension-shear behavior of low-aspect-ratio RC walls[J]. Engineering Mechanics, 2018, 35(S1): 53-61. DOI: 10.6052/j.issn.1000-4750.2017.06.S004
Citation: JI Xiao-dong, CHENG Xiao-wei, XU Meng-chao. Experimental study on tension-shear behavior of low-aspect-ratio RC walls[J]. Engineering Mechanics, 2018, 35(S1): 53-61. DOI: 10.6052/j.issn.1000-4750.2017.06.S004

小剪跨比钢筋混凝土墙拉剪性能试验研究

Experimental study on tension-shear behavior of low-aspect-ratio RC walls

  • 摘要: 强震作用下,高层建筑中部分剪力墙可能出现拉-剪耦合受力的不利状态。该文完成6个大尺寸钢筋混凝土(RC)矮墙拟静力试验,研究了小剪跨比RC墙拉剪受力下的破坏形态、滞回性能、承载力和刚度。试验结果表明:轴拉力水平不同,RC墙试件出现不同的破坏形态,包括:剪切破坏(竖向钢筋平均拉应力水平ns=0)、剪切-滑移破坏(ns=0.23~0.63)和滑移破坏(ns=0.8~1.0);RC墙试件轴心受拉的开裂荷载试验值为理论计算值的0.6倍~0.7倍,轴心受拉的初始刚度和开裂后刚度试验值与理论计算值接近;轴拉力严重影响RC墙的抗侧承载力,当竖向钢筋平均拉应力水平ns=0.63和ns=1.0时,试件的承载力分别比无轴拉试件小54%和76%;轴拉力也导致RC墙的等效抗侧刚度降低,当ns=0.23~0.63时,试件的等效抗侧刚度为无轴拉试件的0.56倍,仅为其初始刚度理论值的1/10。该文建议了拉剪受力RC墙的等效抗侧刚度计算公式,该公式计算值与剪切-滑移破坏试件的试验结果吻合良好。最后,该文对比了各国规范中拉剪承载力计算公式,美国ACI 318-14规范和欧洲EuroCode8规范均低估了小剪跨比RC墙试件的拉剪承载力,试验值与规范公式计算值之比分别为1.90和2.41;而中国JGJ 3―2010规程的RC墙拉剪承载力公式可能安全度不够。

     

    Abstract: Under strong ground motions, some shear walls in high-rise buildings might be subject to combined axial tension and shear forces. This paper presents a series of quasi-static tests in which six large-scale RC wall specimens with low aspect ratios were subjected to axial tensile forces and cyclic shear loadings. The tensile-shear behavior of low-aspect-ratio RC walls was investigated, including the failure modes, hysteretic responses, strength and stiffness. The test results indicated that the failure mode of the wall specimens varied with axial tensile forces, including shear failure (the tensile stress ratio of vertical rebars ns=0), shear-sliding failure (ns=0.23~0.63) and sliding failure (ns=0.8~1.0). Under the axial tensile loading, the experimental values of the cracking tensile load of the wall specimens were 0.6~0.7 times the theoretical values, while the experimental values of the initial tensile stiffness and post-cracking stiffness were close to the theoretical values. The presence of tensile force significantly affected the lateral strength of the RC walls. The specimens of ns=0.63 and ns=1.0 had lower peak lateral loads by 54% and 76% than the counterpart specimen without tensile force, respectively. The presence of tensile force also led to a decrease in the effective lateral stiffness of the wall specimens. The effective lateral stiffness of the specimens of ns=0.23~0.63 was approximately 0.56 times that of the counterpart specimen not subjected to tensile force, and it was only 1/10 of the theoretical value of the initial stiffness. This study recommends the formulas used to calculate the effective lateral stiffness of low-aspect-ratio RC walls under coupled tensile and shear forces. The predicted values from the formulas show good agreement with the test results of those specimens that failed in a shear-sliding mode. Finally, the design formulas specified in various codes were compared with the test results. The ACI 318-14 (United States) and EuroCode 8 (Europe) formulas underestimate the tensile-shear strength capacity of the low-aspect-ratio RC wall specimens in this experimental program, with the ratio of experimental-to-calculated values equal to 1.90 and 2.41, respectively. The JGJ 3-2010 (China) formulas might overestimate the tensile-shear strength capacity of RC walls.

     

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