The forced-based and direct displacement-based methods for seismic design of high-rise reinforced concrete buildings are applied to design rectangular shear walls of 17-storey residential buildings located in Montreal (QC) and Vancouver (BC), Canada. The current Canadian design requirements regarding the inter-storey drift limits, shear force demand and ductility requirements are critically examined in the optics of the behaviour of taller walls. Special attention is directed to the procedures to calculate ductility demand and rotational capacity of the walls on global and local levels. The particular aspects of direct displacement based design methodology for seismic design of taller buildings are outlined and discussed. These include the higher-mode effects, P-Delta effects and the value of the minimum design base shear force. Because NBCC 2010 does not provide directly displacement design spectra that are needed for this design approach, the range of targeted displacements is estimated for the initial design, and later validated with the results of a non-linear time history analysis. Non-linear time history analyses are carried out with the OpenSees program for suites of simulated ground motions compatible with current design spectrum to study and compare the seismic response of walls designed using the two different methods. The non-linear model of the shear wall is developed using fibre sections and considering the material nonlinearity of the concrete and steel reinforcement as well as geometric non-linearity. Results demonstrate that the two methods have limitations for seismic design of taller reinforced concrete buildings.
展开▼
