Residential Towers - USA

The project consists of towers and a large area 3 story building for car parking and plant. We noticed that 2m dia piles, with very heavy reinforcement, were used under this 3 story building and the owner was facing difficulty with the availability of piling contractors able to execute such a large diameter. During our discussions with the consultant on why such a pile was used under this 3 story building, they explained that the original soil was loose with a potential for liquifaction and there is an intended engineered backfill of 3m in 10 layers underneath the ground floor. The massive size and reinforcement of these piles was due to considering a horizontal force on these piles equal to the passive pressure developing from the 3m engineered fill as the land is trying to move towards the sea when the underlying soil liquifies in a seismic event.