Seismic performance comparison of a tall building in Thailand with outriggers and flag walls | |
| Author | Kyi Noo Khin |
| Call Number | AIT Thesis no.ST-25-21 |
| Subject(s) | Tall buildings--Earthquake effects--Thailand Earthquake resistant design--Thailand |
| 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 | This study investigates and compares the seismic performance of a 50-story reinforced concrete residential building in Chiang Mai, Thailand, by evaluating how the outriggers and flag walls influence both global response and local response. Eleven structural models such as core only model, core with outriggers at different locations and core with different flag walls configurations were created to explore the effects of different placements and arrangements of those systems and how they affect the responses of the building. After the initial linear analyses, the configurations that showed the most potential were selected and examined further using nonlinear time history analysis with ground motions matched to the Maximum Considered Earthquake (MCE) level.The results make it clear that outrigger walls and flag walls influence the building in different ways at both the global and local levels. When compared with the core-only model, both systems noticeably improve how the building handles drift, displacement, and overall stiffness. In linear analysis, the selected outrigger and flag-wall configurations reduced maximum drift by 46.23% and 48.75%, respectively, compared to the core-only model. In nonlinear analysis, drift reductions under the X-direction control ground motion were 7.11% for the outrigger model and 10.98% for the flag wall model; under the Y-direction control motion, reductions reached 38.76% and 38.46%, respectively. Even though each system behaves differently, both stay within the performance limits required by ASCE 41-17 for MCE-level earthquakes.In terms of efficiency, the outrigger system required full-height wall extensions that blocked approximately 1.847% of floor area per level and 76.8 m² over four floors, while flag walls obstructed only 0.693% per floor, amounting to 57.6 m² even when installed on eight floors. These findings indicate that, while both systems enhance seismic performance, flag walls provide comparable lateral response improvement with lower spatial impact, supporting more flexible and efficient tall-building layouts.These insights can help engineers make more informed decisions when choosing and placing outriggers or flag wall systems to create safer and more efficient tall buildings in seismic areas. |
| Year | 2025 |
| 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;Anwar, Naveed (Co-chairperson) |
| Examination Committee(s) | Thanakorn Pheeraphan;Krishna, Chaitanya |
| Scholarship Donor(s) | AIT Scholarship |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2025 |