MIKROZONASI SEISMIK WILAYAH PADALARANG, KABUPATEN BANDUNG BARAT MENGGUNAKAN METODE HORIZONTAL TO VERTICAL SPECTRAL RATIO (HVSR)

Abstract

In the last five years, there has been an increase in tectonic activity in the southern region of Java. One of the active faults in the West Java region is the Cimandiri Fault and the Lembang Fault. The Cimandiri Fault is southwest-northeast, while the Lembang Fault is east-west. Through DEM (Digital Elevation Model) satellite imagery, continuity of the fault is estimated to be in Padalarang, West Bandung Regency. The existence of urban connecting infrastructure such as toll roads, railroads, and dense settlements makes the area of fault continuity as an area that has the potential to experience damage during an earthquake. Therefore, in the effort of disaster mitigation, microzonation studies are needed to determine the dynamic characteristics of the soil in the fault area. Horizontal to Vertical Spectral Ratio (HVSR) method is used to estimate the value of dominant frequency and amplification factor from microtremor measurement data. From 42 measurement points, the dominant frequency value (f0) is divided into two zones, 1.4-4 Hz and 4-6 Hz. The amplification distribution (A0) ranges from 2-8, where the area with the highest amplification is around the Cipularang toll road and densely populated settlements. Areas with a high seismic vulnerability index (Kg) are in the villages of Sukatani and Bojongkoneng in Ngamprah District, Situ Ciburuy in Padalarang sub-district and Pasirhalang village in Cisarua sub-district..