Abstract
Taking advantage of an opportunity that the inner part of slurry wall at Kawasaki man-made island for Trans Tokyo Bay Highway was being excavated, we could estimate the effct of soil improvement work done by the offshore sand compaction piles for the said excavation area was as deep as from TP-28.0m to TP-55.0m. We investigated on the quality of sand piles and characteristics of clay in-between the sand piles at each depth after a lapse of four years. It resulted in our confirmation that sand piles installed into the undersea ground has kept good condition in its quality and appearance, and the strength of clay in-between piles increased.
