Response of High-Rise Buildings in Singapore due to a Potential Giant Earthquake in the Sumatran Megathrust

Abstract

The acceleration response spectrum in Singapore from a potential giant earthquake, having an M _w of 8.8, in the Mentawai segment of the Sumatran megathrust is estimated using a recently derived attenuation relationship. Two sets of ground motions recorded at a rock-site station in Singapore are scaled to match the target μ + σ spectrum. The ground motions at two typical soft-soil sites in Singapore are subsequently generated to study the local site effects. Two generic models, namely a 15-story slab block and a 30-story point block, are constructed based on structural systems commonly used in Singapore. The results from dynamic response analysis of the models indicate that the 15-story model will not suffer damage due to the simulated ground motions on soft-soil sites, while the 30-story generic model will have fine cracks in the masonry walls on the upper floors. However, both models show that structural damage is less likely. The floor acceleration responses of the 15-story model imply that occupants on the higher floors would experience vibration corresponding to Modified Mercalli Intensity (MMI) scale of V, while those living on the higher floor of the 30-story building may be subjected to MMI scale of VI. This level of vibration may cause some damage to non-structural components and overturning of unstable objects.

Keywords:

• Singapore
• Sumatra
• Mentawai
• Subduction
• Giant Earthquakes
• Local Site Effects
• High-Rise Building
• Structural Response