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Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In performance-based seismic design of a structure, the inelastic deformation demand of structural members or system is the primary input, whereas in conventional design procedure the input is the equivalent static loads to represent seismic effects. The National Building Code of Canada (NBCC) requires that for irregular and buildings higher than 60 m, dynamic analysis must be conducted to calculate seismic design forces and deflection, while for other cases, equivalent static loads can be used for the design. In this paper, the performance of a 20-story steel moment resisting steel frame building, designed for western part of Canada, has been presented. Simulated and actual (scaled) ground motion records are used to evaluate the dynamic response. While NBCC does not provide any performance-based design method, various techniques for displacement-based design have been explored here in the context of the 20-story building. A wide range of variation amongst these methods in terms of their application and results was found. Amongst these methods the direct displacement-based design method seems to be more suitable for carrying out the performance-based design of a building. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper introduces and assesses the seismic and collapse behavior of a new lateral load-resisting system referred to as steel Moment-Resisting Knee Braced Frame (MKF). A design method following the Performance Based Plastic Design (PBPD) procedure is proposed to analyze the structure and size the structural members. A prototype frame part of an office building located in Vancouver, British Columbia, Canada is then selected to demonstrate the design method and evaluate the performance of the proposed system. The prototype MKF is also designed using the conventional elastic approach in accordance with the National Building Code (NBC) of Canada. The seismic performance and collapse response of the proposed system are examined using the nonlinear static analysis, nonlinear response history analysis (NLRHA) and incremental dynamic analysis (IDA) performed on the prototype five-story MKF under potential sources of seismicity in the west coast of Canada including shallow crustal, subduction interface and subduction intraslab events. Fragility curves are finally developed using results of the IDA to obtain the collapse probability of the system. The results of the analyses are compared to those obtained from a steel Moment-Resisting Frame (MRF) counterpart designed in accordance with the PBPD and elastic approaches. Findings of the study show that the proposed steel MKF can efficiently satisfy the code-specified story drift limit and manifest the yielding mechanism assumed in design. The MKF designed according to the PBPD approach offers the lightest structure among all frames studied and yields a collapse probability lower than that of the MKF designed as per the elastic design method. The proposed system can be used in seismic design of steel multi-story buildings as an alternative to conventional steel MRFs. • A new steel lateral load-resisting system referred to as Moment-Resisting Knee Braced Frame (MKF) is introduced. • A Performance-Based Plastic Design method is proposed to design the system. • The seismic performance of proposed MKFs are evaluated and compared to conventional steel MRFs. • Compared to steel MRFs, the proposed MKF offers similar lateral stiffness and collapse behavior with reduced steel tonnage. • MKF can be considered as a viable alternative to conventional steel MRFs in multi-story buildings. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: This paper investigates the seismic performance of moment-resisting frame steel buildings with multiple underground stories resting on shallow foundations. A parametric study that involved evaluating the nonlinear seismic response of five, ten and fifteen story moment-resisting frame steel buildings resting on flexible ground surface, and buildings having one, three and five underground stories was performed. The buildings were assumed to be founded on shallow foundations. Two site conditions were considered: soil class C and soil class E, corresponding to firm and soft soil deposits, respectively. Vancouver seismic hazard has been considered for this study. Synthetic earthquake records compatible with Vancouver uniform hazard spectrum (UHS), as specified by the National Building Code of Canada (NBCC) 2005, have been used as input motion. It was found that soil–structure interaction (SSI) can greatly affect the seismic performance of buildings in terms of the seismic storey shear and moment demand, and the deformations of their structural components. Although most building codes postulate that SSI effects generally decrease the force demand on buildings, but increase the deformation demand, it was found that, for some of the cases considered, SSI effects increased both the force and deformation demand on the buildings. The SSI effects generally depend on the stiffness of the foundation and the number of underground stories. SSI effects are significant for soft soil conditions and negligible for stiff soil conditions. It was also found that SSI effects are significant for buildings resting on flexible ground surface with no underground stories, and gradually decrease with the increase of the number of underground stories. [Copyright &y& Elsevier]

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study evaluates the seismic response of an advanced hybrid steel‐timber structure using a nonlinear static and dynamic analyses. A three‐story prototype building located in Vancouver, BC, Canada was designed first. The gravity load resisting system (GLRS) consists of cross‐laminated timber (CLT) floor slabs, glulam beams, and glulam columns. The lateral load resisting system (LLRS) includes a chevron‐type steel Concentrically Braced Frame. The numerical model of the structure was then developed in the OpenSees program. Nonlinear hysteresis response of steel braces and timber joints were explicitly simulated. The results of the analysis revealed that the hybrid structure possess an acceptable lateral stiffness while providing sufficient ductility to dissipate seismic energy. No unsatisfactory response was observed in the timber system. [ABSTRACT FROM AUTHOR]