| Summary: | 碩士 === 國立成功大學 === 土木工程學系碩博士班 === 96 === With highly development of the modern traffic, the constructions of high speed rails are more and more widespread through the world. The high speed rails not only bring a convenient, safe, and swift transit system for people, but also produce some annoyances to people, such as ground vibration and noise. The ground vibration caused by moving trains is concerned with the structural supporting system and the properties of soils, which is a complex problem.
This study primarily focuses on the ground vibration due to the train moving on the embankment, and the train model is set to the THSR (Taiwan High Speed Rail). First, this study uses the three dimensional finite element model to simulate the ground vibration and compares with the field experimental results. The result of this study indicates that the characteristics of vibration due to trains moving on the embankment are smaller at low-frequency, and larger at high-frequency. The low-frequency vibration has two peaks at 3 and 10 Hz due to the trainload dominant frequencies of f=NV/L. From the finite element analysis, the influence of rail irregularity is very significant on the vibration response of trains moving on the embankments. Therefore, the best way to reduce the ground vibration is to diminish the rail irregularity. Besides, the rail irregularity will affect the characteristics of the trainload dominant frequencies when trains move on the embankments but very seldom when trains move on the bridges.
Thereafter, this study also investigates the ground vibrations and noise in the Zhonghe Line of Taipei metropolitan rapid transit systems and utilizing the finite element modes of wheels and tracks to proceed the dynamic analysis and probing into the relationship between vibration and noise. The result of this study shows that the high-frequency vibration between 100 Hz to 1200 Hz is primarily the source of noise.
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