Location

Cork Institute of Technology, Cork, Ireland

Event Website

https://event.ceri2020.exordo.com/

Start Date

27-8-2020 11:45 AM

End Date

27-8-2020 1:00 PM

Description

Some types of structures can suffer from vertical irregularities due to aesthetic, functional, or economic reasons. A possible lateral force resisting solution for this type of structures is to use Concentrically Braced Frame (CBF) systems. CBFs are gaining a lot of popularity as their design and fabrication are straight forward with low cost. Moreover, they are overcoming many limitations exist in other lateral force resisting systems. In this paper, a direct displacement-based design (DDBD) procedure is developed for irregular multi-storey CBF structures. In this procedure, design displacements considered are decided upon the code and material drift limits, then the strength required to achieve this displacement is calculated and finally all structural elements are designed. A case study of twelve-storey CBFs with vertical irregularity is designed using the developed DDBD procedure. The configuration of the vertical irregularity assessed is in the form of setbacks up the vertical axis of the building where the frames have more bays at base of the building than at the top. Non-linear time history analysis (NLTHA) using 7 different earthquakes with displacement response spectra matching the design displacement spectrum are used to validate the behaviour of the irregular CBF structure. The case study of twelve-story CBFs with vertical irregularity is used to check the performance of the new design methodology. It is found that the design displacements, storey drifts from the DDBD procedure for the case study with vertical irregularity matched relatively well with the displacements and storey drifts recorded through the NLTHA analyses and a new DDBD procedure for CBFs with vertical irregularity is validated.

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Aug 27th, 11:45 AM Aug 27th, 1:00 PM

Direct Displacement Based Seismic Design of Irregular CBFs

Cork Institute of Technology, Cork, Ireland

Some types of structures can suffer from vertical irregularities due to aesthetic, functional, or economic reasons. A possible lateral force resisting solution for this type of structures is to use Concentrically Braced Frame (CBF) systems. CBFs are gaining a lot of popularity as their design and fabrication are straight forward with low cost. Moreover, they are overcoming many limitations exist in other lateral force resisting systems. In this paper, a direct displacement-based design (DDBD) procedure is developed for irregular multi-storey CBF structures. In this procedure, design displacements considered are decided upon the code and material drift limits, then the strength required to achieve this displacement is calculated and finally all structural elements are designed. A case study of twelve-storey CBFs with vertical irregularity is designed using the developed DDBD procedure. The configuration of the vertical irregularity assessed is in the form of setbacks up the vertical axis of the building where the frames have more bays at base of the building than at the top. Non-linear time history analysis (NLTHA) using 7 different earthquakes with displacement response spectra matching the design displacement spectrum are used to validate the behaviour of the irregular CBF structure. The case study of twelve-story CBFs with vertical irregularity is used to check the performance of the new design methodology. It is found that the design displacements, storey drifts from the DDBD procedure for the case study with vertical irregularity matched relatively well with the displacements and storey drifts recorded through the NLTHA analyses and a new DDBD procedure for CBFs with vertical irregularity is validated.

https://sword.cit.ie/ceri/2020/7/2