Automatic detection of the height of poured concrete via fiber-optic temperature sensing

Abstract

In the process of bridge foundation construction, the height of poured concrete cannot be measured automatically, which depends on manual operation and construction interruption. This paper proposes an automatic detection technology of the height of poured concrete via fiber-optic temperature sensing, which use the small temperature difference between concrete and air medium in the process of concrete pouring. The median filtering method is used to process the temperature position curve to obtain a signal curve similar to a step signal. The step functions with different periods are constructed, and the correlation coefficient curve is obtained by cross-correlation operation between the obtained temperature curve and the step functions with different periods. The variable step size search method is used to improve computational efficiency. Finally, the correlation coefficient curve is processed by peak seeking to realize the automatic discrimination of concrete level elevation. This technology has been successfully applied to the diaphragm wall project of Zhang-Jing-Gao Yangtze River Bridge. Limited by the spatial resolution of the temperature measurement system, the resolution of the liquid level elevation is ± 0.5m, and the automatic judgment of the liquid level elevation is consistent with the actual measurement results judged by the temperature nephogram, indicating that the algorithm has good accuracy, and the results of 30 operations at the same time are consistent, indicating that the algorithm has good stability.