KLASIFIKASI TAPAK LOKAL BERDASARKAN DATA MIKROTREMOR MENGGUNAKAN METODE HORIZONTAL TO VERTICAL SPECTRAL RATIO (HVSR) DI DAERAH EPITERMAL BOROBUDUR KABUPATEN MAGELANG; SITE EFFECT CLASSIFICATION BASED ON MICROTREMOR DATA USING HORIZONTAL TO VERTICAL SPECTRAL RATIO (HVSR) METHOD IN EPITERMAL AREA OF BOROBUDUR MAGELANG REGENCY

Aji, Dendy P, Imam Suyanto

2015 | Skripsi | FMIPA

Microtremor measurements are one of the most popular method to estimate the site effect in an area. This technique is used at 85 measuring points in the epithermal area of Borobudur with the purpose to classify the site effect based on dominant frequency, to correlate the parameter result of data processing with the geological conditions and to determine area that has high vulnerability indices. The data processing method used is Horizontal to Vertical Spectral Ratio (HVSR) popularized by Nakamura. The Parameters of the data processing are Dominant Frequency (F0), Amplification (A0), the thickness of sediment layer (H), and vulnerability indices (Kg). All of the parameters are correlated by geological and alteration map and then interpreted qualitatively. In this research, the result is the site effect classification based on F0. F0 value 0-2,7 Hz is classificated as alluvial sediment, 2,7-5 Hz as prophylitic up to argillic alteration igneous rock and >5 Hz as sillisification alteration. Values of F0, H, and Kg are correlated with geological and alteration map, however there is no correlation between A0 and geological or alteration map. The risky area toward seismic wave is located in the north area of research field with Kg value >30.

Kata Kunci : HVSR; Microseismic; Microtremor