Effects of vertical irregularities on seismic reponses of tall buildings | |
| Author | Thanakorn Chaionnom |
| Call Number | AIT Thesis no.ST-24-14 |
| Subject(s) | Tall buildings--Design and construction Earthquake resistant design |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Structural Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | Tall buildings with vertical irregularities, such as podiums and setbacks, are the majority of the existing tall buildings in Bangkok (82%), which can suffer more damage during earthquakes. Studies of the effects of vertical irregularities of tall buildings are rarely found in previous studies. The main objectives of this research are to study the effects of the presence of the podium and the setback through the parametric study of varying the podium-tower height ratio (HP/HT) and setback-tower height ratio (HS/HT) on story-level and component-level seismic responses. Linear time history analysis (LTHA) and nonlinear response history analysis (NLRHA) are conducted to compare the linear and nonlinear seismic demands. Modal pushover analysis for both linear and nonlinear is also included to see the mode-by-mode contribution. The results show that the podiums and setbacks do not clearly affect the story-level responses, but the component-level seismic demands show a slight localized decrease in seismic shear demands in the seismic-force-resisting elements (core walls) and significantly increase by 110% on the gravity-load-resisting elements (shear walls and columns) with a clear concentration at the podium interface level. This large, increasing force can cause serious damage to the structures. The setback’s presence causes localized increases in seismic demands; these increases are much less than the effects of the podium’s presence.The nonlinearity of the structures caused different internal force distributions. The linear analysis may overlook significant concentrated demands at the location of vertical irregularities, especially on the shear walls and columns, resulting in inadequate design and severe damage to the structures.Nonlinear analysis is recommended for the analysis and design of tall buildings with podiums or setbacks, as elastic analysis cannot precisely estimate seismic demands. |
| Year | 2024 |
| Type | Thesis |
| School | School of Engineering and Technology |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Structural Engineering (STE) /Former Name = Structural Engineering and Construction (ST) |
| Chairperson(s) | Pennung Warnitchai |
| Examination Committee(s) | Thanakorn Pheeraphan;Krishna, Chaitanya |
| Scholarship Donor(s) | His Majesty the King’s Scholarships (Thailand) |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2024 |