Seismic Analysis of an EBF

In this project, Gaurav led the team of 4 members to check the seismic design of an 8 story Eccentrically Braced Frame (EBF) with 5% damping ratio. Gaurav and his team used ETABS. They used ASCE 7-10, AISC 341-16 Seismic provisions, Steel Manual 15th edition, ACI 318-14 to redesigned the building for better ductility but by keeping original symmetry. For load combinations, Gaurav and his team designed all deformation controlled members like links without the over strength factor and their load combinations. For all force controlled members like columns, Gaurav designed them using over strength factor. Gaurav performed Modal Response Spectrum Analysis using SRSS method. At the end, Gaurav and his team performed the detailing of the link members.

Original Building Plan

ETABS Model of the EBF

Bending Moment diagram in left and Shear force diagram at right to verify link presence

Summary Calculation of a Link Design using Steel Manual and ASCE 7-10

Modal Response Spectrum Analysis Inputs in ETABS using SRSS Method

Gaurav and his team included only first 2 modes in the response spectrum as it contributed to 90% mass

MRSA Result- Gaurav and his team found Interstory Drift Values quite safe with the safe limit value of 0.025 specified by the seismic provisions.

MRSA Result - Story Shear along with Base Shear Vb =223.45kips

MRSA Result- Peak acceleration is 81.744 in/sec^2 or 0.212g

MRSA Results- Gaurav found peak displacement as 2.692 in on the roof for above inputs.