Tekka Place was redeveloped from a six-storey mall to a ten-storey commercial retail and hotel tower. The site posed a number of challenges with its basement seated on soft marine clay located within the critical LTA Railway Protection Zone and hemmed in by conserved shophouses.
The team re-engineered the existing basement diaphragm wall assembly with a dual function to support both the new substructures (below ground) construction works and the intensified loadings from the new superstructures (above ground) in the redeveloped Main Block. This innovative re-engineering approach avoided much of the need for new retaining walls and new foundation piles installation, therefore achieving a significant reduction in the project’s carbon footprint by saving substantial amount of concrete and steel reinforcement by 3,400 cubic metres and 400 tonnes. This is equivalent to all the concrete structures supporting the entire 320 hotel rooms in this development. This overall sustainable adaptive reuse approach underpinned by intelligent structural engineering design enabled the project to be executed safely and reduced the construction programme significantly by six months.
The redeveloped 10-storey Tekka Place is located in the Rochor Planning Area – Singapore’s budding arts, culture, and education district. In redeveloping the project, previously solely a mall, to a taller hotel with a basement mall, the team had to consider the sensitivity of nearby conservation shophouses and critical rail infrastructure, built largely on marine clay. The retaining wall was a key feature in all this. The more obvious solution would have been to excavate the plot and build a new retaining wall. However, the team came up with a better solution, prioritising safety and the integrity of surrounding structures, and upholding SJ’s commitment to sustainability.
The team decided to re-engineer the existing retaining wall to serve two purposes through a complex undertaking. The first was the original purpose of holding the soil behind it. The other is to serve as the foundation for the columns of four storeys.
For overcoming the challenges of a delicate building project, the SJ Development Management and Engineering & Specialist Services team won the BCA’s Design and Engineering Safety Award in 2021.