జర్నల్ ఆఫ్ సివిల్ అండ్ ఎన్విరాన్‌మెంటల్ ఇంజినీరింగ్

Plastic Hinge Length Requirements in Reinforced Concrete Couple Shear Wall Buildings for Seismic Reinforcement Detailing

Abstract

SK Amjad Hossain* and Bagchi Ashutosh

Proper reinforcement detailing in plastic hinge regions is one of the important measures that could help damage control of structural walls subjected to any severe earthquake event. Inelastic curvatures are commonly assumed to be uniform over a height called plastic hinge length. Non-linear dynamic analyses are performed on a set of coupled shear wall buildings of simple configurations for different heights. Inelastic curvatures are calculated on numerous heights of all the buildings and plotted along with the height of the buildings. Plastic hinge lengths are estimated with the yield curvatures from analytical results. It becomes a common practice to estimate the plastic hinge length equal to 0.5 to 1.0 times the wall length, which basically were developed from experimental studies on beam and column elements. As per the Canadian standards CSA A23.3-04, the requirements to calculate plastic hinge lengths are identical for both cantilever and coupled shear walls, i.e., 1.5 times the wall length in the direction under consideration. Results from the present study show that inelastic curvatures are not uniform over the plastic hinge length and the Canadian requirement as per CSA A23.3-04 to calculate plastic hinge length is unconservative for couple shear walls and more critical for slender coupled shear walls. And the plastic hinge length calculation as per Canadian code CSA A23.3-14 (clause 21.5.2.1.2) is over conservative for coupled shear wall buildings and much more over conservative for slender coupled shear walls. A comparison studies with different researchers and building codes are made. A new multiplication factor is proposed for the safe estimation of plastic hinge length for couple shear walls of medium and high rise reinforced concrete buildings. Results indicate that it needs to consider 2.0 times wall length instead of 1.5 times wall length in the direction under consideration for the safe estimation of coupled shear wall plastic hinge length calculations.