Performance-based seismic design of building structures

Abstract

Direction du Patrimoine de I'edition 395, rue W ellington Ottawa ON K1A 0N4 CanadaBien que ces formulaires aient inclus dans la pagination, il n'y aura aucun contenu manquant. i * i Canada Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. AbstractA new method for the displacement-based design (DBD) of a variety of structures to resist the earthquake forces experienced by them is developed. The proposed method requires the determination of yield and ultimate displacements of the structure. For preliminary design these parameters are determined from approximate empirical relationships. The required strength of the structure is then determined from the inelastic demand spectrum corresponding to the ductility capacity and the estimated yield strength.The method can be used for a multi degree of freedom system by transforming it into an equivalent single degree of freedom system.For final design, a modal analysis is carried out on a model of the structure that is based on its preliminary design. A pushover analysis of the structure for forces that are distributed according to the first mode now provides better estimates of the yield and ultimate displacements. These refined estimates are then used to obtain a more precise value of the required strength. Iterations may have to be carried out to obtain convergence between the assumed and calculated values of the design displacements.Finally, to account for the effect of higher modes in shear wall structures and high-rise moment resisting frames, the standard modal pushover analysis (MPA) method available in the published literature is used.ii Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Nonlinear time history analyses of the structures designed according to the proposed DBD method are carried out for sets of ground motions that are compatible with the design response spectra. Procedures for the selection and scaling of the spectrum compatible ground motions are studied. A set of such ground motions that is compatible with the UHS of Montreal corresponding to a probability of exceedance of 2% in 50 years is developed as a part of the present research. This set and a similar set for Vancouver, developed in another research study, are used in time history analyses, first to develop relationships between inter-story drift and roof drift, and second to validate the proposed DBD method. iii Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.(3.11) Inter-story drifts, 12-story SMRF building in Vancouver 126 xi Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. beams 132 (3.2) Stress-Strain relationships for (a) Concrete and (b) Reinforcing Steel 133 (3.3) Displacement Based Design of 12-Story RC Frame In Vancouver-first try 134 (3.4) Pushover Curve-Initial design 134 (3.5) Displacement Based Design of 12-Story RC Frame In Vancouver-second try 135 (3.6) Columns and be...

Performance-based plastic design method of high-rise steel frames

“…To ensure the expected ductility demands and energy dissipation capacity, some appropriate detailing measures should be taken. When hit by the strong earthquakes, however, the structures designed by the above methods will suffer inelastic deformations, which is very difficult to predict and control [1][2][3][4][5][6][7][8][9]. The inelastic behavior may include severe yielding and buckling of structural members and connections.…”

Displacement-based seismic design of RC wall-frame buildings and asymmetric plan buildings

“…These procedures employ a variant of the capacity spectrum method in which the demand is represented by an inelastic response spectrum plotted in the acceleration displacement format for a ductility that is determined from estimates of the yield displacement and acceptable ultimate displacement. Details of the procedures have been presented by Ghorbanie-Asl (2007), Ghorbanie-Asl (2005, 2006) and Humar et al ( , 2010). Humar and Ghorbanie-Asl (2005) introduced a practical displacement-based design procedure in which the maximum acceptable displacement demand on building structures was limited to the least of displacement capacity of the critical component, displacement dictated by performance criteria, and displacement limit to prevent P-A instability.…”

“…Through examples of the design of several reinforced concrete, and steel momentresisting frames as well as braced frames Ghorbanie-Asl (2007) showed that within a few iterations one could estimate the yield and ultimate displacement capacities of the system accurately.…”