To consider how to determine optimized space between piles in late Pleistocene Holocene deposits in the lower area of the Sai Gon River

The report presents methods of determination of optimal distance of piles in the geotechnical condition of the late Pleistocene-Holocene deposits in the lower area of the Sai Gon River which ensures the safe construction, economic efficiency, as well as stability of neighborhood constructions, especially for big and heavy constructions. Sai Gon 2 bridge is used as an example with geotechnical characteristics at the construction-site as following. The considered result of the optimal distance of piles at the Sai Gon bridge construction-site was suggested to be 2.75D which is not as 3D as the Vietnamese standard, TCVN 10304:2014 (Pile Foundation – Design Standard: TCVN 10304 – 2014, 2014). Simultaneously, it should note the phenomena of flowing sand from -25 to -65 m and measure the horizontal pressure for countermeasures or maintenance solutions in the bored pile working.