Historical Background and Technology of Dredged Material Solidification and Pumping Method Circa 2000

Historical Background and Technology of Dredged Material Solidification and Pumping Method Circa 2000
From the end of the 1990s to the 2000s, Japanese ports and harbors became decrepit and slow to accommodate large vessels, necessitating the dredging of shipping lanes and berths throughout the country. At the same time, environmental regulations were tightened for the conventional method of dumping dredged soil at sea, and land disposal sites were tight in urban areas, so technology was needed to reuse dredged soil as a resource. Against this backdrop, the dredged soil solidification and pumping method was introduced. In this method, dredged soil is mixed with solidifying materials and pumped as fluidized solidified soil to be reused as backfill for revetments and road embankments for reclaimed land. Solidification makes dredged soil with high water content easier to handle and reduces problems such as foul odor and scattering. This was a breakthrough in terms of converting dredged soil, which was previously a waste product, into a resource. In the 2000s, as environmentally c
onscious port development progressed, this method was highly evaluated by both the Ministry of the Environment and the Ministry of Land, Infrastructure, Transport and Tourism, and its effects were reported in terms of reduced transport distances and CO2 emissions. The method was also applied to the improvement of bottom sediments in rivers and lakes, and attracted attention as a construction method that reduces the load on the surrounding area because of its ability to be used in continuous construction. The dredged material solidification and pumping method was introduced at a time of transition from port construction to port maintenance and harmony with the environment, and has become a symbol of the changing times in port infrastructure.