Title: Influence of Design and Construction Practices on Seismic Behavior of Reinforced Concrete Buildings
Author(s): Samir A. Ashour, Khalid Mahmood,and Amir, and Hamdy H. Abdel- Rahman
Publication: Symposium Paper
Appears on pages(s): 1001-1016
Keywords: columns (supports); compressive strength; concrete construction; detailing; earthquake-resistant structures; frames; reinforced concrete; residential buildings; standards; structural design; Design
The quality of in situ concrete construction in developing countries is affected by a number of factors. These factors may include absence of national standards and codes of practice, use of approximate methods of analysis and design, substandard materials, poor construction practices, and inadequate quality control and inspection procedures. Defects and failures may occur due to these factors that may affect the useful life of a structure. This paper evaluates the seismic behavior of reinforced concrete buildings designed and constructed by following the usual procedures in Saudi Arabia. Behavior of typical reinforced concrete frames is investigated by using nonlinear time-history analysis and Takeda hysteresis model. The factors considered in the study include compressive strength of concrete, detailing of reinforcement, and size and orientation of columns in the frame. The results show that while the frames remained elastic when subjected to an earthquake of low intensity (0.09), they developed inelastic behavior exceeding the ductility capacity at some point when subjected to an earthquake of moderate intensity (0.24). It has been also found that the orientation of columns, particularly the interior ones, has a substantial effect on the building resistance to earthquakes. The compressive strength of concrete, through it has a crucial effect on the overall behavior and durability of a building, did not significantly affect the primary moment-curvature relationships of under-reinforced member sections considered in the study when its specified value was lowered by 20 percent. A critical study of reinforcement detailing shows clearly an urgent need for implementing a national code of practice for concrete buildings in Saudi Arabia.