基于Fisher函数的水泥路面板底脱空判别方法

Discrimination method for cement road slab void based on fisher function

针对水泥路面板底脱空病害识别率低、缺乏理论依据等问题,提出了适用于声振法的Fisher函数判别水泥路面板底脱空的方法。利用短时傅里叶变换克服了傅里叶变换在声音信号时频转换时的缺点,实现了时间和频率的定位功能,提高了分辨率。提出了表征水泥混凝土路面脱空的共振峰频率、共振峰振幅、功率谱面积等声音特征参数,通过大量样本建立了Fisher脱空判别函数,确定了水泥板板底脱空判别标准。在多个实体工程的试验和应用中通过注浆量、定位取芯落差等多种方法,对脱空检测结果进行了验证,结果表明该方法的脱空识别准确率在90%以上,并具有便捷、速度快等优点。

Aiming at lack of theoretical basis and low identification rate for cement road slab void discrimination, a new method to discriminate this problem based on Fisher function applicable for the acoustic-vibration method was proposed. Using short-time Fourier transformation to overcome shortcomings of Fourier transformation in audio signal conversion from time domain to frequency domain, the positioning of time and frequency was achieved, the discrimination veracity was improved. The sound characteristic parameters of cement slab void including resonance peak frequency, amplitude, power spectrum area and so on were presented. Through a large number of samples a Fisher function was established. The discrimination standard for cement road slab void was built. Fisher function discrimination method was applied in a number of engineering projects and verified with grouting volume, positioning core gap and other methods. The results showed that the veracity of the proposed cement road slab void discrimination method is over 90%, and more convenient and faster than other methods.