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A platform for research: civil engineering, architecture and urbanism
Vertical Irregularity of Buildings: Regularity Index versus Seismic Risk
The seismic performance of buildings with irregular distribution of mass, stiffness, and strength along the height may be significantly different from that of regular buildings. Design codes prohibit construction or recommend special seismic design of such buildings depending on the level of irregularity and site hazard. It is generally believed that the regular buildings have a dominant fundamental mode participation in their seismic response and as the irregularity increases the contribution of higher mode increases. Accordingly, previous studies have proposed methodologies to quantify the vertical irregularity of the buildings in terms of their fundamental mode properties. This paper checks the adequacy of fundamental mode properties for the quantification of vertical irregularity. Further, this study attempts to check the correlation between existing vertical irregularity indicators and the seismic risk. Seismic risks of selected vertically irregular buildings in terms of fragility curve, annual probability of collapse, and drift hazard curve indicates that there is no correlation between existing vertical irregularity indicators based on fundamental mode properties and seismic risks. Results of seismic risk analysis show building frames with open-ground story and floating columns are found to be more vulnerable than a similar regular building. However, stepped and setback building frames perform even better than a regular frame. Therefore, stepped and setback buildings under the category of vertical geometric irregularity needs to be investigated in detail to validate the special design requirements recommended by design codes.
Vertical Irregularity of Buildings: Regularity Index versus Seismic Risk
The seismic performance of buildings with irregular distribution of mass, stiffness, and strength along the height may be significantly different from that of regular buildings. Design codes prohibit construction or recommend special seismic design of such buildings depending on the level of irregularity and site hazard. It is generally believed that the regular buildings have a dominant fundamental mode participation in their seismic response and as the irregularity increases the contribution of higher mode increases. Accordingly, previous studies have proposed methodologies to quantify the vertical irregularity of the buildings in terms of their fundamental mode properties. This paper checks the adequacy of fundamental mode properties for the quantification of vertical irregularity. Further, this study attempts to check the correlation between existing vertical irregularity indicators and the seismic risk. Seismic risks of selected vertically irregular buildings in terms of fragility curve, annual probability of collapse, and drift hazard curve indicates that there is no correlation between existing vertical irregularity indicators based on fundamental mode properties and seismic risks. Results of seismic risk analysis show building frames with open-ground story and floating columns are found to be more vulnerable than a similar regular building. However, stepped and setback building frames perform even better than a regular frame. Therefore, stepped and setback buildings under the category of vertical geometric irregularity needs to be investigated in detail to validate the special design requirements recommended by design codes.
Vertical Irregularity of Buildings: Regularity Index versus Seismic Risk
Bhosale, A. S. (author) / Davis, Robin (author) / Sarkar, Pradip (author)
2017-01-23
Article (Journal)
Electronic Resource
Unknown
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