基于BOTDA的混凝土管双裂缝监测试验研究

为研究光纤传感器在短距离内混凝土管出现多缝情况下的布里渊频移特征,设计了系列双裂缝间距的板材拉伸试验;通过试验所得布里渊频移结果得出以下结论:当双缝间距小于50 mm,难以区分裂缝个数;当双缝间距大于50 mm,且小于200 mm时,频移图的拟合波峰区间发生了变化;当双缝间距大于200 mm,频移图峰值点会发生变化,最后,通过混凝土管压力试验,验证了利用分布式光纤监测混凝土管裂缝的有效性。

Experimental Study on Double Crack Monitoring of Concrete Pipe Based on BOTDA

In order to study the Brillouin frequency shift characteristics of optical fiber sensor in the case of multiple cracks of concrete pipe in a short distance,a series of plate tensile tests with double crack spacing are designed.The results of Brillouin frequency shift obtained from the tests show that when the distance between two cracks is less than 50 mm,it is difficult to distinguish the number of cracks.When the distance between two cracks is greater than 50 mm and less than 200 mm,the range of fitting wave peaks of the frequency shift diagram changes.When the distance between the two joints is more than 200 mm,the peak point of the frequency shift diagram changes.The concrete pipe pressure test is designed to verify the test results of the plate.