考虑信号衰减及叠加修正的反射波曲线分析方法

缺陷反射信号的衰减、多缺陷反射信号的叠加以及缺陷形态是低应变曲线分析中影响缺陷特征识别的关键因素。考虑波动在缺陷界面入射前和反射后传播衰减系数的差异以及缺陷反射的叠加干扰,通过完整桩段理论反射波曲线部分拟合受测桩实测反射波曲线及叠加修正获得波动衰减系数,提出基于实测曲线拟合的完整性系数计算改进方法。同时,基于成层土中渐变缺陷桩瞬态响应模拟技术,提出结合完整性系数进一步分析缺陷特征的方法。最后,结合实测反射波曲线验证了方法的有效性。

Method for analyzing reflection wave curve considering signal attenuation and superposition correction

Attenuation of defect reflection signals, superposition of multiple defect reflection signals, and defect shapes are key factors that affect the recognition of defect features during the analysis of low-strain curves. In view of the difference in the attenuation coefficient of wave propagation before incidence and after reflection at the defect interface and the superimposed interference of defect reflection, this paper obtains the attenuation coefficient of wave propagation by partially fitting the measured reflection wave curve with the theoretical reflection wave curve of an intact pile segment and utilizing superposition correction. In addition, the paper proposes an improved method for calculating the integrity coefficient based on measured curve fitting. At the same time, based on the transient response simulation technique of gradually varied defect piles in stratified soil, this paper puts forward the method of further analyzing defect features with integrity coefficient. Finally, the paper verifies the effectiveness of the method by employing the measured reflection wave curve.