Seismic performance improvement of low-rise RC frame buildings with soft first story by using buckling restrained braces | |
| Author | Tariq, Hasan |
| Call Number | AIT Thesis no.ST-16-02 |
| Subject(s) | Buildings, Reinforced concrete--Earthquake effects Structural frames |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Structural Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. ST-16-02 |
| Abstract | RC frame buildings with soft first story is one of the common building feature that suffered significant damage in past earthquakes around the world. Hence these type of buildings present high vulnerability and it is economically feasible to retrofit these buildings then to replace them. The metallic yielding device with stable hysteretic behavior and high energy dissipations capacity called as buckling restrained brace (BRB) is proposed to retrofit these type of buildings. In this thesis application of BRBs for retrofitting of low-rise buildings with soft story is presented. In this regard two buildings with soft first story are chosen as case study buildings. Their seismic performance before and after being retrofitted with BRBs are evaluated by using nonlinear static push over and three dimensional nonlinear dynamic analysis. The seismic performance of un-retrofitted building exhibited poor behavior, where all the inelastic deformations were concentrated at the columns of first story leading to soft story mechanism. The adopted retrofitting strategy was to provide additional lateral strength and sufficient stiffness to control the soft story mechanism at the first story. BRBs were the main retrofitting scheme used in this study. The results obtained from nonlinear analysis show that BRBs can significantly improve the seismic performance of the building with soft first story. In regard to further reduce the damage on the structure, BRBs with low yield strength steel were also utilized. Their seismic assessment prove that damage is mainly concentrated in the added brace and the response of the building was more or less elastic. So, BRBs with low yield strength steel can significantly reduce plastic deformation of the columns, thus inhibiting the soft story mechanism. Later on this recent retrofit scheme using BRBs is compared with other traditional retrofit schemes such as adding infill walls and FRP wrapping of columns. Their comparison reflect that BRBs serve as the most effective solution is terms of achieving the desired performance objective, having less effect to the buildings occupancy and offering easy post-earthquake repair and replacement. Hence the results clearly demonstrate the potential of BRBs in seismic retrofitting of soft story buildings. |
| Year | 2016 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. ST-16-02 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| 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) | Anwar, Naveed ;Punchet Thammarak; |
| Scholarship Donor(s) | Asian Development Bank-Japan Scholarship Program (ADB-JSP); |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2016 |