Behavior of Existing High-Rise Building with Soft-Story under Bangkok Earthquakes

Abstract

Technological developments and space constraints have made high-rise buildings popular in Bangkok. Number of conditions resulted in many high-rise buildings being designed and constructed with soft-story. The soft-story makes buildings weak to earthquakes. Earthquake-resistant design standard of the Department of Public Works and Town & Country Planning (DPT) was announced in 2007 and last updated in 2018 (DPT 1301/1302-61). In this standard, the condition for determining the uniformity of the vertical stiffness of the building, which is used as a criterion to judge whether a building has a soft-story or not, was established. The standard also stipulates that the response analysis of soft-story buildings under earthquakes requires only time-historical analysis methods. This study focuses on behavior of the existing high-rise building with soft-story in Bangkok, that was designed and constructed before the law required to take into account the effects of earthquakes, under earthquake. The case study in this paper is an existing high-rise reinforced concrete building with soft-story in Bangkok. There are a total of 34 floors and a total height of 129.60 meters. Considering the standard criteria, the 7th floor structure is considered as a soft-story. Details of time-history responses of the building under the earthquake ground motions for Bangkok area will be presented and discussed in this paper.