Numerical Simulation of Vibration Level Meter for Estimation of Train-induced Ground Vibration
石井 武司 ,
金田 淳齋藤 邦夫
17 , 2016-03-31
This paper presents a calculation method to give numerical value same as a vibration level meter. The vibration level is determined to an index to evaluate environmental vibration by laws and ordinances. The level must be measured by a vibration level meter which conforms to Japan Industrial Standard C 1510-1995. On the other hand, the evaluation of a prediction and countermeasures of the ground vibration often depends on the numerical calculation such as the finite element method based on the dynamic analysis theories. Generally, the vibration is evaluated by acceleration in these calculations. Therefore, it is necessary to convert an acceleration into vibration level. The level meters are made of two circuits to simulate human body responses for frequency and time. Firstly, the acceleration wave is converted from a time domain to a frequency domain by Fourier transfer. The converted acceleration passes a weighting filter expressing the human body responses. The acceleration is inverse Fourier transformed. Then, effective values of the acceleration wave in a time domain are calculated by performing exponential average processing. Finally the vibration level is calculated by substituting this effective acceleration for a definition equation. The validity and the precision of the calculation method were confirmed based on measurement data provided at points along some viaducts.