小湾拱坝三级配混凝土动态弯拉力学特性试验研究

Experimental study on dynamic flexural-tensile mechanical behavior of three-graded concrete in Xiaowan Arch Dam

对小湾拱坝工程三级配混凝土动态弯拉力学特性进行了试验研究。试验采用液压伺服加载系统和简支梁三分点加荷法,共进行了21个试件试验,尺寸是300mm×300mm×1100mm。静载试验时,加载速率为250N/s。动载试验时,考虑了不同初始静载(0%、40%、80%)和不同动态加载方式(冲击和变幅三角波)。试验结果表明,初始静载对混凝土动态极限弯拉强度影响很大;合适比例的初始静载,对混凝土动态极限弯拉强度有利;同静载相比,冲击加载时混凝土动态极限弯拉强度提高,弯拉极限拉伸值变小,纯弯区正截面中和轴位置基本不变;往复加载对混凝土存在低周疲劳的不利影响。研究结果为小湾高拱坝抗震安全评价提供了依据。

The experimental study on dynamic flexural-tensile mechanical behavior of the three-graded concrete in the arch dam of Xiaowan Hydro Project by using third-point loading method for simply supported beam was carried out.Twenty one specimens with dimensions 300mm×300mm×(1 100)mm were adopted.In the static loading tests,the loading rate was 250N/s.In the dynamic loading tests,different initial static load and different dynamic load patterns,including the impact wave and triangular wave with variable amplitude,...