Estimasi Karakteristik Dinamis Tanah Untuk Pemetaan Daerah Rawan Bencana Gempa Bumi Berdasarkan Data Pengukuran Mikrotremor di Kota Solok

Abstract

The soil dynamic characteristics can provide information about the soil layer structure which can be used for basic infrastructure development and natural disasters mitigation, especially earthquakes. This research has been conducted to estimate soil dynamic characteristics for earthquake vulnerable zone mapping based on microtremor measurement data in Solok City. Microtremor single station data were analyzed using HVSR method and microtremor array data were analyzed using SPAC method. The soil dynamic characteristics estimated in this research includes the value of dominant frequency, peak amplitude, seismic vulnerability index, peak ground acceleration, ground shear strain, shear wave velocity and sediment layer thickness. The results showed that Solok City has a dominant frequency values ranged from 0,42 Hz to 4,91 Hz, peak amplitude ranged from 1.92 to 8.47, seismic vulnerability index ranged from 1.72 to 108.01, peak ground acceleration ranged from 99,36 to 115,43 gal, ground shear strain ranged from 1,887x10-4 to 1,242x10-2, shear wave velocity ranged from 149.02 to 192.46 m/s and sediment layer thickness ranged from is 9.8 m to 110.86 m. The soil dynamic characteristics distribution generally indicates that Solok city area is quite high potential building damage due to the earthquakes. The results showed that the highest eartquake vulnerable zones include most area in Kelurahan Kampung Jawa, north part of Kelurahan Nan Baimo, and west part of Kelurahan Laing.