Liquefaction mitigation using stone columns.
The project
The project developed by Sonatrach was for the construction of a liquefied natural gas train consisting of three tanks, with a storage capacity of more than 316,000 m3 of gas.
The challenge
The soil study report indicated soils composed of soft clay and sandy layers requiring treatment up to 25 metres deep, despite the presence of compact layers between nine and 12 metres deep.
The solution
To treat the liquefaction of the soil, Keller installed more than 62,500 ml of stone columns (with load handling provided by piles). The stopping depths of the stone columns was predetermined by zoning according to the soil tests (depth from 12 to 25 metres). Different predrilling techniques were also used in the dense soil layers between 9 and 12 metres.