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Performance Based Seismic Design (PBSD)
Performance based seismic design is currently the major topic of research in many earthquake research centers worldwide, where it
is aimed to replace the current code practice of design by a new code based on the performance of the structure under certain earthquake loading.
BUT What's wrong with the current practice of seismic design?
Current codes of practice such as International Building Code and The Uniform Building Code, assure only minimum requirements of losses and mainly aims to protect the structure
occupants; this might seem enough, but to us engineers the economical life cycle of the structure matters and is considered a main aspect of design.
UBC 1997, SECTION 1626.1 : “The purpose of the earthquake provisions herein is primarily to safeguard against major
structural failures and loss of life, not to limit damage or maintain function”
But losses due to an earthquake extends further than just losses in lives or injury of occupant; there is also losses accompanied to the damage of the structure, and indirect losses due to downtime associated with loss of use of the building, these losses are of major importance to the owners of structures and they are usually disappointed with the results when an earthquake hit their structures that are conforming to the code requirements.
From here the demand for a new design approach that can define the performance of the structure under certain earthquake was developed to address the issues of damage control and loss reduction; this design approach is the Performance Based Seismic Design (PBSD).
The basic concept of Performance Based Seismic Design is to provide engineers with the capability to design buildings that have a predictable and reliable performance in earthquake. Further, it permits owners and other stakeholders to quantify financially or otherwise the expected risks to their buildings and to select a level of performance that meets their needs while maintaining a basic level of safety.
The general methodology of PBSD is shown in the figure;
The most recent research carried in the field of PBSD is the ATC-58 Project, which aims to find a code that relates the performance of structures to the structural design process.
Currently the new code is 35% completed, you can review the draft reports and other information at the the ATC website, and the other references shown below.
References
