From the four Sewerage Treatment Plant (STP) administration buildings, Keller designed DSM columns for two of the buildings while the other two on stone columns to create a value-engineered multiple product solution.
The project
The four administration buildings at the Tubli Sewerage Treatment Plant were planned on ground with a variable soil profile. Seeking a more cost-effective alternative to conventional piling, Dada Bhai Construction approached Keller to develop a suitable solution that would meet the project's performance requirements while reducing foundation costs.
The challenge
Variable subsurface conditions comprising loose to medium dense gravelly, silty sands overlying weathered calcisiltite and carbonate siltstone presented foundation design challenges for the four administration buildings. With building loads varying across the site, the client required a cost-effective alternative to piling that could deliver the required bearing performance while allowing rapid handover for subsequent foundation construction activities.
The solution
Keller designed two administration buildings on 1.0m diameter DSM columns 7.5m deep and the other two on stone columns, providing a cost-effective alternative to piling. The DSM solution enabled immediate commencement of load transfer and foundation works, avoiding the delays typically associated with pile testing, trimming, and acceptance procedures.