Eccentric punching tests on column bases ‐ Influence of column geometry
Eccentric punching tests on column bases ‐ Influence of column geometry
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DOI：
10.1002/suco.202100744
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发表时间：
2022-03
影响因子：
3.2
通讯作者：
J. Ungermann;Philipp Schmidt;G. Christou;J. Hegger
中科院分区：
文献类型：
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作者：
J. Ungermann;Philipp Schmidt;G. Christou;J. Hegger
中心加载柱脚的试验研究提供了当前冲切设计规定的基础。然而，这种对称荷载条件在日常工程实践中是一个例外，因为通常会发生荷载偏心，导致沿控制周长沿着的剪应力分布不均匀。为了考虑这种影响，设计方法定义了不同的因素，以增加作用剪力或减少设计中的冲切阻力。14个偏心加载和4个中心加载柱脚的新冲压试验结果现在允许根据不同的几何边界条件评估设计方法。在这个新的试验系列中，荷载偏心率进行了系统分级，以分析其对冲切性能的影响。柱脚连接处混凝土多轴受压区的应变测量揭示了柱脚冲切破坏的新见解。因此，切向混凝土应变和冲切剪切强度的降低之间的相关性可以识别为增加荷载偏心率。根据欧洲规范2、模型规范2010和下一代欧洲规范2的稳定版本，将实验确定的荷载增加系数与设计结果进行比较，揭示了未来获得更先进设计规定的优化潜力。
Experimental investigations on centrically loaded column bases provide the basis for current punching shear design provisions. However, this symmetric loading condition represents an exception in daily engineering practice since usually load eccentricities occur leading to uneven shear stress distributions along the control perimeter. To account for this effect, design approaches define different factors to either increase the acting shear force or to decrease the punching shear resistance in design. New punching test results of 14 eccentrically loaded and four centrically loaded column bases now allow the evaluation of design approaches depending on different geometric boundary conditions. In this new test series, the load eccentricities were systematically graded to analyze their influence on the punching behavior. Strain measurements in the multiaxial compression zone of the concrete in the column‐footing connection reveal new insights on the punching failure of column bases. As a result, a correlation between tangential concrete strains and the reduction of punching shear strength can be recognized for increasing load eccentricities. The comparison of experimentally determined load increase factors with the design results according to Eurocode 2, Model Code 2010 and the stable version of the next generation of Eurocode 2 reveals optimization potential for deriving more advanced design provisions in the future.