Seismic Hazard Maps of Bengkulu City, Indonesia, Considering Probabilistic Spectral Response for Medium and Stiff Soils

This paper presents the extended work of a seismic hazard map for Bengkulu City, Indonesia. In this current study, seismic hazard maps are generated by considering site variations in Bengkulu City, Indonesia.

First, site investigation data is collected. Furthermore, the probabilistic spectral response for Bengkulu City is analysed. The spectral matching method is implemented to obtain appropriate ground motion considering the most dominant earthquake scenario that occurred. A seismic ground response analysis is conducted to obtain several ground motion parameters, such as peak ground acceleration, spectral acceleration values at 0.2 s and 1 s, and ground motion amplification.

The results show that peak ground acceleration in the study area is generally within the range of 0.5 to 0.6g. It indicates that most sites in Bengkulu city could undergo strong motion. Spectral accelerations at 0.2 s and 1 s are also dominantly found in the range of 0.9 to 1.2g and the range of 0.5 to 0.7g. Generally, ground motion in the study area could amplify up to 1.1 to 1.5.

Spectral acceleration curve for site classes in Bengkulu City shows a similar trend to other spectral accelerations. It indicates that the spectral acceleration proposed in this study could be implemented in the study area.