导纳法在预制板轨道充填层施工质量无损检测中的应用

Application of mobility method in nondestructive testing of construction quality of precast slab track filling layer

文章以地铁预制板轨道自密实混凝土充填层施工为研究对象,开展导纳法无损检测充填层施工质量应用,对比分析充填层补浆前后的导纳信号变化。研究结果表明:补浆前,2块预制板式无砟轨道测试得到导纳率最大分别为6.789、6.171,分别为导纳率基准值的11.11倍和10.1倍,缺陷位置处的导纳率远远大于灌注质量良好位置处的导纳率,说明充填层存在缺陷,也证明导纳率能较敏感地反映缺陷;补浆后,灌注质量良好的轨道板导纳率数值较低,基本在2.5以下波动,说明补浆后充填层已无明显缺陷。导纳法能有效检测城市轨道交通预制板轨道自密实混凝土充填层的缺陷,对板式无砟轨道施工质量检测和补浆效果验证有较强的指导意义。

Taking the construction of self-compacting concrete filling layer for metro precast slab track as the research object,the paper carries out the application of admittance method to nondestructive testing the construction quality of filling layer,and compares and analyzes the admittance signal changes before and after filling.The research results show that before grouting,the maximum admittance rates of the two precast slab ballast less tracks tested are 6.789 and 6.171 respectively,which are 11.11 times and 10.1 times of the reference admittance rate respectively.The admittance rate at the defect location is far greater than that at the location with good grouting quality,which indicates that the filling layer has defects,and also proves that the admittance rate can more sensitively reflect defects.After grouting,the admittance value of track slab with good grouting quality is low,basically fluctuating below 2.5,indicating that the filling layer has no obvious defects after grouting.The mobility method can effectively detect the defects of the self compacting concrete filling layer of the precast slab track of urban rail transit,and has a strong guiding significance for the construction quality testing of the slab ballast less track and the verification of the grouting effect.