THE PRACTICAL DENSITY MEASUREMENT OF SUSPENDED SPRAYED CONCRETE DUST BY USING ARTIFICIAL NEURAL NETWORK

The suspended dust generated in the tunnel construction work is one of the causes for tunnel workers becomes Pneumoconiosis. Therefore, the ministry of Health, Labor and Welfare of JAPAN dictated the employer has a management duty to measure the density of suspended dust twice a month from 2008. Ordinary, the density measurement of suspended dust had done by the digital dust meter. However, the digital dust meter is expensive and it need the measuring time for 10 minutes. In addition, it require the conversion coefficient factor individually. The simpler measurement method for the density measurement becomes stringent. It is well known among the tunnel engineer that the suspended dust reflects flashlight during flashed photography. By using this phenomenon, the authors proposed the dust density measuring technique for suspended dust by the flashlighted image of digital camera. In this study, the authors propose the simple dust measuring technique by using artificial neural network. And the authors applied it in real tunnel construction site, and compare with the results obtained by the digital dust meter, and the effectiveness of this method was confirmed.