利用竖向加速度的水泥路面错台估算方法

Faulting estimation method based on vertical acceleration of cement concrete pavement

针对目前人工错台检测方法效率、可靠性及安全性差的现状,提出了一种利用竖向加速度的错台估算方法.首先,对采集后的加速度信号,利用5层Daubechies小波实现降噪处理,将加速度序列映射为灰度图像,利用接缝的周期性,实现接缝定位;其次,由加速度-灰度映射图得到每块板上最大加速度值gm的位置分布、板块相同位置处加速度累加平均值ge和绝对值累加平均值ga,用以分析加速度在接缝附近的变化特征,从而构建表征错台的加速度特征量.实验表明:gm位置在板块上近似随机分布,错台与加速度的峰值并无相关性;ge和ga曲线在接缝附近的波峰位置、幅值与错台的相关性较弱;ga曲线在接缝附近的增量与错台相关性较好,由此构建的特征参数af值,与错台具有良好相关性,可以实现快速、客观地错台估算.

The inefficient, less traditional faulting distress detection method is a manual detection method, which is reliable and dangerous to use. To overcome these shortcomings, a new automatic detection method based on statistics values of vertical acceleration was proposed. Firstly, noise reduction was applied to acceleration signals by 5 layers Daubechies wavelet, acceleration sequence was put forward from the acceleration-gray map and a new joint location method based on the joint periodicity in the acceleration sequence was obtained. Secondly, three statistic parameters were adopted to analyze the acceleration variation near the joint, which included the position distribution of peak acceleration values （gin） as well as the accumulative mean of acceleration values （ ge ） and the accumulative absolute mean of acceleration values （ go ） at the same position on each slab from the acceleration-gray map. Test results show that the position distribution of peak acceleration values （gm） on slabs is similar to random distribution, peak acceleration values have no relation with faulting distress. The position of peak values and the amplitude near each joint on curves of g~ and ga have weak relation with faulting distress. The increment near each joint on the curve of ga has fair relation with faulting distress. Based on the analysis, a new acceleration statistic parameter （af） was put forward to estimate the faulting value, which had good relation with faulting distress.