箱梁中冲击回波主频影响因素研究及应用  

Influencing factors on impact-echo characteristic frequency in a box beam

作　　者：邹春江[1] 陈征宙[1] 董平[1,2] 邢姝[1] 缪世贤[1] 韩非[3] 

机构地区：[1]南京大学,南京210093 [2]南京南大工程检测有限公司,南京210008 [3]南京大学地球科学与工程学院,南京210093

出　　处：《振动与冲击》2010年第7期126-131,共6页Journal of Vibration and Shock

基　　金：江苏省交通科学研究计划项目(05Y16)

摘　　要：箱梁预应力孔道注浆的饱满度尚缺乏有效的检测方法。冲击回波法作为新型的无损检测手段,被应用到注浆饱满度的无损评价上。通过研究箱梁中冲击回波主频的各种影响因素,如板厚、孔道深度、d/T、孔道影响的范围、注浆强度和饱满度等,研究主频在箱梁中的响应规律,最后得到了无浆孔道的判断依据。在实验数据的基础上,还总结出孔道为空的砼板主频经验方程,并给出了系数的经验取值。最后对典型测区进行了成像,一般可清晰看到管道的位置,通过比较孔道处实测主频和同等情况下空孔道的理论主频,可判断管道的注浆情况。此外,还绘制了典型测线各测点的主频曲线。最终判定1个测区的注浆有缺陷,凿开后验证为空洞,并给出了凿开后的照片。说明冲击回波方法可以有效地评价箱梁预应力孔道的注浆饱满情况。There is no effective method to test voids in post-tensioning ducts.As a new elastic wave method,impact-echo method (IEM) was used to evaluate grouting fullness.Through studying influencing factors on impact-echo characteristic frequency in a box girder,such as,thickness of flat,depth of duct,d/T,influencing area of duct,grouting strength and fullness,the laws of the characteristic frequency in the box girder were studied,and the judgment rules of voids was obtained.On the base of experimental data,an empirical formula calculating the characteristic frequency of a concrete deck with voids in its duct was deduced,and the value of the coefficient μ was given.Last,8 test areas were studied,and the color pictures were given according to the characteristic frequency of each test area.The position of the ducts and the grouting fullness could be known from the pictures.One of these test areas was judged to have voids in its ducts.Then its ducts were chiseled out,and the result was verified.The photos of the voids were given here.IEM was proved to be an effective method to evaluate grouting fullness in post-tensioning ducts.

关 键 词：冲击回波法 箱梁 主频 预应力孔道 注浆饱满度 

分 类 号：TU757.1[建筑科学—建筑技术科学]