Development of Seismic microzonation for Rancaekek Sub-District using microtremor method

Rancaekek sub-district located in the Bandung Regency is geologically characterized by soft and loose sediment layers such as clays, silts, and sands associated with the old Bandung Lake. Due to the existence of the Sesar Lembang Fault, the Rancaekek area is also vulnerable to seismic disasters. To provide knowledge on seismic vulnerability, therefore, a seismic microzonation study was conducted at 25 locations in the Rancaekek area using the microtremor method. Based on the available microtremor measurement data, the seismic vulnerability of the Rancaekek sub-district varies from one area to another. Amongst other areas Northern part of Bojongloa, Northern part of Rancaekek Wetan and Northern part of Jelegong areas are the most vulnerable to seismic damage because these areas have low dominant frequencies with medium amplification zones, and low Vs30 values ranging from 90 to 127 m/s. Thus, any building and infrastructure development in these areas should follow the national building code to reduce damage due to earthquake shaking.