Development of a measurement method for abrasion irrigation channel using underwater ultrasonic wave
Japan has many concrete irrigation channels with total length of about 400,000 km. Most of these channels are now too old for continued use. It would be too costly to reconstruct these channels. The concrete surfaces of the channels have been abraded by the flow of water and sand. The roughness of the concrete surface causes a decline in the water flow function. Over the years, considerable attention has been paid to the measurement of the arithmetic mean roughness. However, a method that can measure roughness underwater has not yet been developed. The purpose is to develop a sensor able to measure roughness underwater. We propose a method using underwater ultrasonic waves. We used 200 kHz frequency sensor. We measured the reflected waves and analyzed the peak to peak. We examined four experiments. The propagation loss became larger as the distance was reduced. The theoretical value and the measured value showed good agreement. The dispersion of measured values stabilized within 0.5% using a 10-point moving average. The measurement range was considered and found to be 300 mm. Its application to measure roughness was considered by testing the relationship between the measured value and the arithmetic mean roughness as measured by another method. The measured value decreased as the arithmetic mean roughness increased. The determination coefficient R2 at a distance of 500 mm was 0.91. The R2 at a distance of 1000 mm was 0.79. The results of these experiments show that the underwater ultrasonic wave sensor is an effective tool for underwater.
KeywordsUnderwater ultrasonic wave Abrasion Irrigation canal Peak to peak Arithmetic mean roughness
This work was supported by the Sasakawa Scientific Research Grant from The Japan Science Society.
- Asano I, Tokashiki M, Mori M, Nishihara M (2014) Development of erosion monitoring system on laser displacement meter for cementitious surface coating method. Irrig Drain Rural Eng 82(5):285–296Google Scholar
- ASTM E 965 (2001) Standard test method for measuring pavement macrotexture depth using a volumetric technique. ASTM International, West ConshohockenGoogle Scholar
- Kawakami A, Asano I, Mori M, Kawabe S, Tokashiki M (2017) Abrasion measurement method using a profile gauge. Irrig Drain Rural Eng 85(1):77–84Google Scholar
- Maniwa Y (1985) Characteristics of underwater sound. Inst Noise Control Eng Jpn 9(2):61–64Google Scholar
- Okajima K, Nagaoka S, Ishiguro S, Ito R, Watanabe K, Ito T (2016) Measurement of the roughness of the concrete surface by the peak to peak value of the aerial ultrasonic wave. Irrig Drain Rural Eng 84(3):233–240Google Scholar
- Takemura T, Tanji H, Araragi Y (2001) Study on a method to estimate coefficients of roughness. Irrig Drain Rural Eng 69(5):477–480Google Scholar
- Thop WH (1961) Analytic description of the low frequency attenuation coefficient. Acoust Soc Am 42:270Google Scholar