Assessment of Direct Displacement Based Seismic Design Philosophy for Reinforced Concrete Frame Buildings
No Thumbnail Available
Date
2011-11
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
Structural displacements and member deformations do not enjoy a primary role in the current
force-based seismic load resistance design. Their absolute magnitude is of interest only for
aspects considered of secondary importance for seismic performance and safety. In the main
phases of current force-based design, namely that of member dimensioning for given strength
demands and that of detailing, structural displacements and member deformations enter in an
average sense and indirectly. Recent years have seen, however, an increased interest in
absolute magnitude of displacement and deformations as the basis of seismic design. The
main reason for this is the recent recognition that displacement rather than strength, demands
and capacities is what determines seismic performance and safety. Since an earthquake is
dynamic action, it represents for a structure a demand to withstand certain displacement and
deformations, but not specific forces. In this work the recent displacement based design
philosophy is assessed, examined and compared with the current traditional force-based
design philosophy as applied for reinforced concrete frame buildings by taking representative
frame buildings without structural wall to be analyzed using both methods so that the
limitations and suitability of the recent method can be drawn as well as the parameters to be
considered is examined by taking span length, story height, beam depth and number of
stories as a parameter. The parametric study shows that this new design philosophy accounts
parameters those affect the response of the structure directly in transparent way. Specially,
the span length and beam depth have significant influence on the resulting strength
requirement. It is also simple for practical application in addition to its basic on convincing
and logical theoretical back ground. In this thesis work, a lot of effort have been done to
introduce the world wide trend of shifting the design philosophy towards displacement-based
which and also help further researchers to insight the detail researchable areas those guide for
the revision of our seismic design building standard codes.
Description
Keywords
direct displacement based design, design displacement, substitute structure, equivalent damping