Seismic hazard microzonation of ground response parameters in Bengkulu City, Indonesia

Abstract

This paper presents the seismic hazard microzonation of ground motion parameters on the basis of earthquakes events in Bengkulu City. Geotechnical site investigation and geophysical survey were performed in Bengkulu City. Furthermore, data were used to observe the geological condition. The local seismic design code for soft soil was used to generate spectral acceleration, which was later used as the scaling factor to generate ground motion for earthquake simulation. One-dimensional seismic ground response analysis was conducted to simulate earthquake wave propagating through soil layers. Several parameters, such as peak ground acceleration (PGA), spectral accelerations (SA) at 0.2 s and 1 s, and seismic wave amplification factor were observed. Those parameters were also depicted in seismic microzonation maps and addressed to identify potential impact during the earthquake. The results showed that the possibility of structural building responses along coastal area of Bengkulu City is relatively high. Therefore, a local seismic design code is important to propose as the alternative for reliable seismic design code. In general, the results of this study could give a recommendation to local government to consider seismic resistance design for buildings in Bengkulu City.