Natural Frequency Analysis Using Raspberry Shake 4D on the Diponegoro Education Dam

The Diponegoro Dam is an educational dam that is used for many activities. The vibration of the dam is important to monitoring for mitigation assessment. This mitigation research uses a passive method, Horizontal Vertical Spectral Ratio (HVSR), and spectrum methods. The HVSR method obtains natural frequencies (f0) and amplification, spectrum method to obtain vibration frequencies. The data that has been recorded via an accelerometer 3 component. The research data contains of 9 primary data taken using an accelerometer, which used the Raspberry Shake 4D. This study aims to determine the distribution of the natural frequency and the resonance values. The research results are natural frequency values of 0,50 to 50,0 Hz and resonance values of 1.8 to 2.7 mm/s2. The amplitude resonance on line 1 from 1,8 to 2,7 mm/s2 and on line 2 ranges from 1,8 to 2,7 mm/s2. Line 1 and line 2 resonance values do not show any resonance. The direction of particle movement shows the dominant horizontal direction (northeast-southwest). The water flow and failing water on the Diponegoro dam drain system cause vibration on the dam. The Diponegoro dam is in good condition.