when structures are subjected to strong ground motion excitations, structural elements may be prone to yielding, and consequently experience significant levels of inelastic behavior. the effects of inelastic behavior on the distribution of peak floor loads are not explicitly accounted for in current seismic code procedures. during recent years, many studies have been conducted to develop new de...

It is impractical and uneconomic to design a structure that remains elastic throughout severe ground motions. The main design philosophy is that minor structural damages are acceptable as long as the structure does not collapse. Hence, seismic base isolation of structures provides a better alternative in constructing seismic resistant structures. A fixed-base structure designed in accordance to...

in recent years, seismic evaluation and vulnerability of the existing buildings, that have been designed based on an earlier seismic design code or designed without seismic design criteria, has been very important. in this paper, the seismic evaluation and vulnerability of concrete buildings, using an old 5- story building with shear walls as an example has been discussed. for this building, fi...

The paper is an analysis of buildings behavior during strong earthquakes, considering the modifications of the structural dynamic characteristics due to strong earthquake generated damages. The study is focused on the difference in a building behavior, function of the mode the structure is situated relative to the seismic ground motion from the spectral point of view: below resonance or above r...

In the current engineering practices, buildings are commonly designed for an effective lifetime of 50 years. This lifetime can increase the cost of buildings with short lifetimes and can reduce the safety level of buildings with large lifetimes. In this paper, a “service-life factor” has been defined. Applying this factor into the nominal values of live, earthquake, wind, and snow loads, the ef...

This paper investigates the elastic-plastic seismic behavior of long span cable-stayed steel bridges through the plane finite-element model. Both geometric and material nonlinearities are involved in the analysis. The geometric nonlinearities come from the stay cable sag effect, axial force-bending moment interaction, and large displacements. Material nonlinearity arises when the stiffening ste...

The design of earthquake-resistant buildings starts with defining the maximum lateral earthquake forces or their resultant. The amount of these forces depends on various factors, including coefficient of system behavior which depends on overstrength and its ductility. In this study, a method is presented for designing an earthquake-resistant system in which the distribution of lateral forces is...

Interaction between a structure under base excitation and heavy non-structural elements that it supports is significant in the seismic analysis and design of the structure. Heavy non-structural elements may slide/rock under base excitation, and this dynamic action affects the seismic behavior of the supporting structure. Hence, in this study, a numerical model was presented to describe the seis...

Evaluated is the accuracy of the modal pushover analysis in estimating the seismic demands for six SAC buildings, excluding gravity-loads and P-delta effects. These results are compared with those obtained by nonlinear response history analysis and three force distributions in FEMA-273.