| Summary: | 碩士 === 國立臺灣大學 === 土木工程學研究所 === 91 === The Taiwan HRS is under construction. Its route will pass though the Tainan Science-Based Industry Park (TSIP) that is newly developed for the high-tech industry. In order to evaluate the influence of the ground vibration caused by the high-speed train, that is sensitive to the high-tech factories in TSIP, the National Science Council constructed a full-scale pile foundation in TSIP and conducted a series of vibration simulation tests. Among them, the single pile vibration test will be investigated in this report.
The single pile vibration test includes the forced vibration test by harmonically shaked exciters and the drop-hammer impact test. At first, the test results are deduced in this report, then an axisymmetric finite element method by using the computer program ABAQUS is used to simulate the vertical forced vibration test and the drop-hammer impact test of single pile. Results obtained from ABAQUS are then compared with the test results.
The results of test are divided into three sections. Firstly, the results of forced vibration test are expressed in terms of the RMS velocity; the decay coefficient of ground vibration and the dynamic response functions are deduced. Secondly, the results of drop-hammer impact test are expressed in terms of the 1/3-octave frequency spectra and the decay coefficient of ground vibration. Finally, the results of strain gage are attached to the steel bar inside the pile are investigated.
Based on the result of test, it shows that the RMS velocities of ground in the forced vibration test are around 50-80 dB. For horizontal forced vibration test, the displacement dynamic response functions of pile head and nearly ground show significant response when the test frequency is below 10 Hz. As for the vertical force vibration test, the displacement response of pile head decreases with respect to the frequency. The drop-hammer impact test can produce significant ground vibration in the frequency range of 6~50Hz and the ground vibrations generated are around 70-90 dB.
For the simulation of vertical forced vibration test, the responses of pile head obtained are in good agreement with the results of test. For each measuring point on ground, results obtained are similar to the test results only at low frequencies. As for the drop-hammer impact test, the Fourier spectra of ground vibrations can be simulated by the ABAQUS analysis.
|
|---|
