| Summary: | 碩士 === 國立成功大學 === 建築學系碩博士班 === 93 === IC technology advancement and precision manufacturing industries bloomed in the past decades. Owing to their demands for sensitive production environment, strict requirement for floor vibration are ever growing. Floor vibration sources may come from ambient vibration, traffic induced vibration, or construction work. How to reduce or predict the floor vibration level in a new plant becomes a new frontier for research.
This research measured ambient vibration condition of nine buildings. Comparisons were made to understand the vibration reduction characteristics from ground soil into the building. Two base-isolated buildings were also studied to compare the effect of LRB dampers. Different thickness test floor specimens were manufactured and tested. The purpose was to identify the relationship between the floor thickness and inherent damping ratio.
By measuring the nine buildings’ ambient vibration and testing different thickness floors with impact loading test, the following conclusions are drawn:
1.The basement covers with or without soil has the most influence on abatement of ambient vibration in low frequency (under 8Hz).
2.To analyze the abatement of ambient vibration by one-third octave bands theory, a conclusion can be drawn that the buildings with base isolator do not help to decrease ambient vibration.
3.In the test of floor impact loading, we discovered that increasing the thickness of floor will as well increase damping ratio (when the thickness of the floor doubles, the damping ratio also increases by 1.5~2 times).
4.In the test of floor impact loading, if we move a stand kick inward, the natural frequency of Floor B and Floor C have increased by 1.47 times and 1.28 times; moreover, so does the damping ratio has increased by 1.82 times and 2.17 times. Otherwise, after we opened four holes in each floor then finding out that not only the natural frequency of Floor B and Floor C have decreased by 0.98 times and 0.97 times but also the damping ratio has decreased by 0.89 times and 0.84 times.
|
|---|
