|dc.description.abstract||Collapse of reinforced concrete structures under earthquakes is the main reason for life loss.
Thus, avoiding structural collapse under strong earthquakes is the aim of seismic codes. The
aim of the current study is to lead to an improved understanding of the seismic progressive
collapse behaviour of reinforced concrete frame structures and to identify the most important
parameters that should be considered in seismic progressive collapse analysis. The Applied
Element Method, AEM, is an innovative method for direct progressive collapse simulation, in
which strong geometric nonlinearity, element separation and collision can automatically be
considered. Most previous studies focused on side-sway collapse modes only and indirectly
checked for vertical collapse modes.
A validation of the AEM for seismic progressive collapse simulation has been carried
out. The AEM models of three different frame structures have been validated by comparing
the analytical and experimental results. The results have indicated that the AEM can simulate
the structure response from linear range up to collapse reasonably well.
Sensitivity studies have been conducted to rank the material parameters most important
to the collapse process in terms of the time at incipient collapse and to investigate their
effects on the possible failure modes. The results show that the most important parameters are
the parameters that can alter the failure mode.
An investigation on the effect of inclusion of the vertical ground motions on the
collapse capacity and the possible failure modes has been performed. Considering vertical
ground motions in collapse assessment of irregular frame structures has led to a decrease in
the collapse capacity and to modifications in the possible failure mechanisms resulting in
vertical rather than side-sway collapse modes.
A correlation study for investigation of the effect of using different intensity measures,
fifteen spectrum and structure based intensity measures, for scaling far- and near-field ground
motions for seismic assessment of mid-rise frame structures has been carried out. Employing
intensity measures that account for the spectral shape has led to a considerably better
correlation with the engineering demand parameters than utilizing intensity measures that are
based on a single spectral value or a combination of two spectral values.||en_US