| Summary: | 碩士 === 國立成功大學 === 建築學系 === 88 === In the morning of the 21th of Sept.1999, an earthquake with magnitude of Richter scale 7.3 made lots of damages in the North and Central district of Taiwan. Over 10,000 houses were collapsed. In the disaster area, most of the collapsed buildings were low-rise RC Street-Front Mixed-Used buildings. The purpose of this paper is to find out the main reasons for the damages of all low-rise RC Mixed-Used buildings from the structural system, construction quality and the building code. Finally we propose several samples in good structural system and recommend some suggestions during designing RC Mixed-Used buildings.
First we design 3 RC Mixed-Used buildings by using Aseismic Building Code of Taiwan. Then applying non-linear spectrum, we analyze the aseismic capacity of these buildings. During investigating the influence of the structural system, 3 cases with different structural system are analyzed and the differences in seismic resistance among them are compared with each other.
The results of this paper are as followings :
1. The main reasons for the damages of RC mixed-used buildings are collocating as followings : the earthquake force was too great, the structural system and the construction quality were not sound enough.
2. The influence of the strength of concrete in low-rise RC buildings is slight.
3. The influence of hoop space is slight to the low-rise RC buildings damaging in flexural failure.
4. If the soft-story exists, the actual aseismic capacity is only 70% of the design objectives.
5. Setting extra RC shear walls at the back of the buildings is one of the best methods of solving the soft-story problem.
6. The result of accurate design calculation, good construction quality and lacking of soft-story is to ensure the actual aseismic capacity of building matching design objectives. All the above work cannot ensure a building being able to resist an earthquake with forces greater than that defined by the building code.
7. The concept of “Strong column weak beam” emphasized in the building codes cannot be fulfilled in Chi-Chi earthquake. So for the low-rise RC buildings, the ductility should not be emphasized. Instead we should emphasize the strength.
8. The good structure systems of Low-rise RC mixed-used buildings are collocating as: U type, L type, I type with 2 shear wall beside the stair in 1F parallel to the corridor and I type with shear walls at the back of the building.
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