Журнал гражданской и экологической инженерии

The Failure Mechanism of Reinforced Concrete Couple Shear Walls and Coupling Beams- A Ductility Approach

Abstract

Sk Amjad Hossain1* and Ashutosh Bagchi2

The coupled shear wall system is one of the effective potential options in midrise and high rise reinforced concrete buildings design. In seismic design consideration it is very important to ensure that the flexural displacement capacity which is known as ductility should be greater than flexural displacement demand. Non-linear dynamic analyses are performed on 12 storey slender coupled shear wall buildings in 14 different models as per Canadian Code CSA-A23.3 14, except the coupling beams are modelled with conventional reinforcements. Inelastic rotational and curvature demand of 06 coupling beams on each building at different level which are modelled with conventional reinforcements are investigated and the results are compared with US building codes, ACI-318-19, ATC 40 and FEMA-273-356. Investigation shows that coupling beams modelled with conventional reinforcements the inelastic rotational and curvature demand are within the capacities. It has been observed also the overall flexural displacement capacity of the seismic force resisting system of 12 story coupled shear wall buildings in 14 different models in ductility approach. Curvature ductility demands are calculated from those models which are the function of displacement ductility demand and also the plastic hinge length. In ductility approach calculations it was observed that the maximum flexural compression zone length limitation without confinement reinforcement as per (CSA A23.3 1994) is not working with slender coupled shear wall (tension or compression wall), while considering the plastic hinge length as per CSA- A23.3 04 or CSA-A23.3 14; Separate formula has been proposed for maximum compression zone length limitation for coupled shear wall design in ductility approach.