The new three-storied building for ASMA school was to be founded on piles but Keller’s alternative design and build solution on DSM proved cost effective with major time savings on handover compared to piling.
The project
A new G+2 academic block was planned for the ASMA THAT-AL-NITAQAYN Girls Primary School. Keller was engaged to develop a foundation solution for the main building and pump room that could safely support the structural loads on a mat foundation while limiting differential settlements to within the specified design criteria.
The challenge
The site comprised 2.0 m of gravelly sand overlying a thin layer of weak sandstone, underlain by very stiff silt and clay strata becoming firmer with depth. The foundation stress distribution identified concentrated load zones beneath the building columns, requiring local ground improvement to achieve the required modulus of subgrade reaction and control differential settlements within the specified limits.
The solution
Keller developed a value-engineered by installing 0.8 m and 1.0 m diameter DSM columns beneath the high-stress zones of the mat foundation, extending to a depth of 7.5m. The solution provided a cost-effective alternative to piling, delivering the required settlement control while enabling rapid handover to the main contractor, resulting in significant programme savings.