高碾压混凝土坝泄洪时,坝体的振动特征是反映其是否安全运行的重要指标。为探明高碾压混凝土坝的损伤振动响应特性,基于理论分析和数值模拟方法,以坝体典型裂缝和碾压成层结构为损伤性结构指标,对无损伤坝体、裂缝损伤坝体、成层损伤坝体和双损伤坝体的流激振动响应规律进行了对比分析。结果表明:碾压成层强度越低、碾压厚度越大、碾压层数越多,拱坝的流激振动响应越大。针对碾压成层和裂缝损伤建立4种不同的损伤模型,进行动力响应计算,得出:碾压成层结构以及裂缝结构,都会使得拱冠梁以及坝肩部位和损伤部位的动力响应增大;并且当同时存在2种损伤时,2种损伤还将相互影响,使得坝身的动位移进一步增大,对坝身安全最为不利。

The vibration property of dam body is a significant indicator reflecting the security of high roller compacted concrete(RCC) dam under flood discharge. To reveal the response characteristics of damage vibration of high RCC dam, we analyzed and compared the regularities of flow-induced vibration response of dam body in conditions of no damage, crack damage, layered damage, and double damage via theoretical analysis and numerical simulation based on the theory of high RCC arch dam engineering and the damaged structural indicators of typical dam body cracks and layered RCC structures.Results showed that lower rolling layer strength, larger rolling thickness, and more rolling layers could exaggerate the vibration response. By establishing four damage models of different rolling layers and crack damages to analyze the dynamic response, we found that both layer structure and crack damage structure could expand the dynamic response on crown beam,abutment and the damaged sites, and in addition, affect each other in the presence of two patterns of damage,further boosting the dynamic displacement of the dam body, which is the most unfavorable for dam safety.