Mobile QR Code QR CODE : Journal of the Korean Society of Civil Engineers
Title Evaluation of Fundamental Period of Rockfill Dam Using Blasting Vibration Test
Authors 김남룡(Kim, Nam-Ryong) ; 하익수(Ha, Ik-Soo)
DOI https://doi.org/10.12652/Ksce.2012.32.5C.185
Page pp.185-192
ISSN 10156348
Keywords 사력댐;고유주기;발파진동;실지진 계측기록;자유진동 rockfill dam;fundamental period;blasting vibration;instrumental earthquake record;free vibration
Abstract The objective of this study is to present and verify a method for evaluating the fundamental period of a rockfill dam using artificially generated vibration from a blasting event. In this study, the artificial blasting vibration tests were carried out at the site adjacent to the existing Seongdeok Dam for the first time in Korea. The artificial vibrations were induced by 4 different types of blasting with the various depths of blasting boreholes and the various explosive charge weight. During the tests, the accelerations time histories were recorded at the crest of the dam. In this acceleration history, only free vibration decay part following the main vibration event was extracted and it was analyzed by frequency domain analysis using Fast Fourier Transform (FFT). From the results of FFT, the fundamental period of the target dam was evaluated. It is found that the effect of different blasting types on the fundamental period of the target dam is negligible and the fundamental period of the target dam can be consistently obtained by blasting vibration tests. Furthermore, it is found that the period of the target dam calculated by the method using blasting vibration test is similar to that obtained by the method of previous researchers using the real earthquake records. Therefore, in case that the earthquake record is not available, the fundamental period of a rockfill dam can be reasonably evaluated if blasting vibration test is allowed at the site adjacent to the dam.