桥梁预应力孔道结构内部若存在不密实区或空洞等缺陷,会影响结构的承载能力和耐久性,因而孔道注浆质量的无损检测成为确保大型结构安全运营的关键措施.首先从理论上探讨了应力波检测预应力桥梁孔道注浆质量的原理和方法,提出了评价孔道注浆质量的参数,接着对应力波在预应力桥梁孔道注浆检测中的应用开展模型试验研究,进而进行现场检测分析,并与桥梁孔道注浆实际缺陷进行对比.结果表明,应力波法检测预应力桥梁孔道注浆质量信息全面,效果好,检测中所发现的缺陷位置与实际桥梁孔道注浆的缺陷位置有较好的一致性,且检测受环境干扰小,方便快捷,证实了应力波检测预应力桥梁孔道注浆质量的可行性、有效性和无损性.

This paper studies the vibration characteristics of the phononic crystal beam on elastic foundations, based on the Euler beam theory and the Winkler foundation model. The finite element method is used to obtain the band structures of phononic crystal Euler beams. The results reveal the influence of the foundation constraint on the bending vibration band gaps in the phononic crystal Euler beam. The computational results of the band structures of the phononic crystal Euler beam without foundation are compared with those on the elastic foundation. The significantly different band gaps of the model are shown.. The influences of different component ratioes of the phononic crystal Euler beam model are also studied, as well as the frequency ranges of the vibration band gaps.