Horizontal-to-vertical spectral ratio of ambient noise vibrations for local site effects estimation in ITERA

International Conference on Science, Infrastructure Technology and Regional Development

自然科学（总论）

Sudibyo, M.R.P.^1 ; Fattah, E.I.^1 ; Suhendi, C.^1 ; Rizki, R.^1

Geophysical Engineering Program, Institut Teknologi Sumatera, Lampung Selatan, Lampung, Indonesia^1

关键词: Amplification factors;    Horizontal-to-vertical spectral ratios;    HVSR;    Microtremors;    Microzonation;    Predominant frequency;    Site amplification;    Spectral ratios;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/258/1/012041/pdf
DOI  :  10.1088/1755-1315/258/1/012041

学科分类：自然科学（综合）

来源: IOP

【 摘 要 】

Local site effects related to the local geology can influence the damage caused by an earthquake, by amplifying or de-amplifying the ground motion. To characterize the site effects in a local area, the natural frequency and the amplification factors can be estimated by performing Horizontal-to-Spectral Ratio of the ambient noise vibrations recorded. This method is applied by recording the ambient noise in 1.5x1.5 km2 ITERA campus area, deploying 11 points of measurements originally with 500 meters in spacing and 4 additional points with 125 meters in distance to the westernmost points. The recording of 45 to 60 minutes long for each point has been done to accommodate the lowest possible natural frequency we may obtain. However, some data contain too high amount of noise that we have to eliminate them. The HVSR estimation shows that there are two predominant frequency, F0 and F1. F0. The west-south area of ITERA tends to be more slightly vulnerable than the north and east area. The amplification factors Ao are varied from 2.5 to 9 and is considered as the low bound of the real amplification factor.