Analysis of long-distance earthquake tremors and base shear demand for buildings in Singapore

The seismic faults which cause long distance earthquakes for Singapore have been analysed and the maximum possible earthquake in each of these faults have been identified. A seismic hazard predictive model developed from geophysical principles, known as the component attenuation model (CAM), has been used to estimate the bedrock motion in Singapore. CAM has been validated by comparison of the estimated ground motion parameters with historical attenuation data. Earthquakes considered in the study originated from the Indonesian Arc and the Burmese Arc in the south-western part of the Eurasian plate spanning between 90°E and 105°E, and between −5°S and 25°N. An earthquake of 7.6 in Richter Magnitude, from a 400 km distance has been shown to be critical for buildings up to 25 storeys. The elastic base shear demand corresponding to this bedrock motion when accounted for amplification by soft soil is found to be below 10% of the weight of the building.