Singapore’s newest integrated resort, Marina Bay Sands, was completed in record time and has garnered numerous engineering awards. The development sits on recent sand reclamation, which in turn rests on deep soft marine clay deposits. With an average excavation depth of around 18 metres, the 16 hectare waterfront development involved some of the largest marine clay excavation in Singapore. About 2.8 million cubic metres of fill and marine clay were excavated from the site equating to about 800 trucks a day for two years.
To overcome the challenges of the bulk excavation and minimise shoring in difficult soil environments, innovative excavation solutions were developed to enable an accelerated construction timetable for this project involving densely packed site works with complex staging and interface issues. These included the use of unsupported circular excavations up to 130 metres in diameter and continuously reinforced 1.5 metre thick diaphragm walls acting in shear. To add to the challenge, a 35 metre deep ‘cut and cover’ tunnel next to the Singapore’s longest bridge was required. To enable the bridge to tolerate the inevitable imposed lateral displacements of an abutment, the structural system of the existing bridge was modified to allow it to safely articulate in plan.
Jack has many years of experience in geotechnical design. Having graduated from Adelaide University in 1973, working with CSIRO and completing a PhD at Nottingham UK, he joined the Arup geotechnics team in London in 1980 and transferred to Hong Kong in 1993 before retiring in 2014. Jack also became a specialist in geotechnical earthquake engineering after visiting Mexico City’s earthquake site in 1985. He believes that engineering design requires a thorough understanding of the various failure modes to ensure an adequate margin against them. Both geotechnical and seismic design provide a wide range of challenges when attempting to follow these principles.
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