ANALYSIS OF DREDGING WORK AND IMPROVEMENT OF DREDGING PRODUCTIVITY BY USING A UBIQUITOUS DREDGING MONITORING SYSTEM

摘要

In order to maintain both a low water content in dredged soil-water mixtures and consistency of dredging work it is important to analyze systematically the sequence of the dredging work. Nevertheless, in the case of dredging work by a small cutter suction dredger (CSD), vacuum pressures measured at the intake of the dredging pump which are influenced by several sources - dredging soils, surrounding conditions of the cutter operation, fluctuations in the soil-water mixture density, dredging method etc. would be monitored to estimate the water content (dredging density). However, the industry is without any suitable instrument being available for dredging production in Korea. This paper outlines how dredging work by a small cutter suction dredger of 600 hp class is optimized using real time data obtained from a ubiquitous dredging monitoring system which includes a radioactive density meter, ultrasonic flowmeter, pressure and vacuum gauge, and a tachometer for the pump speed. This paper also presents the reduction in the water contents of the dredging mixture required by the filter press with the use of an automatic density control valve to adjust the average water content of the dredging mixture As a result of applying the ubiquitous the dredging monitoring system to the dredging work site, both a construction cost reduction totaling approx. US$3 million and a reduced working period each year were achieved. This paper outlines the first successful case of enhancing the efficiency and the productivity of dredging work by utilizing the systematic results of a dredging research project in Korea.