溪洛渡大坝混凝土芯样动态轴拉试验研究

Dynamic uniaxial tensile test of Xiluodu concrete dam cores

利用MTS大型静、动材料试验机对溪洛渡大坝混凝土芯样开展了动态轴向拉伸试验研究,试验共计32个φ220 mm×440 mm圆柱体试件。试验分别开展了不同应变速率(1×10^(-6)/s、1×10^(-4)/s、5×10^(-4)/s、1×10^(-3)/s)下静、动态单调加载和预加不同初始静载(0%、30%、60%)的单调动态加载(5×10-4/s)。大坝混凝土芯样试验成果,揭示了当前溪洛渡大坝混凝土的静态抗拉力学特征及在动态荷载作用下抗拉强度、峰值应变和吸能能力等随应变速率的变化规律,以及初始持续静态荷载对动态抗拉性能的影响。通过试验数据拟合及统计分析,建立了溪洛渡大坝混凝土的抗拉应力应变曲线解析表达式。试验成果将为溪洛渡大坝抗震深化研究提供科学依据。

Dynamic uniaxial tensile tests was carried out on the concrete drill core of Xiluodu Dam by using MTS large-scale static and dynamic material testing machine.A total of 32 cylindrical specimens ofφ220 mm×440 mm were tested.The experiments were carried out with monotonic loading under different strain rates and dynamic monotonic loading with different initial static loads(0%,30%,60%)preloaded.The test result of concrete dam core samples reveal the static tensile mechanical characteristics and the variation law of tensile strength,ultimate tensile strain and energy absorption capacity with strain rate under dynamic load of Xiluodu Dam concrete,as well as the effects of initial continuous static loads on dynamic tensile properties.The analytical expression of the tensile stress-strain curve of Xiluodu Dam concrete is established by mean of the fitting of test data and statistical analysis.Provide a scientific basis for the in-depth study of the earthquake resistance of Xiluodu Dam.