The simplified nonlinear models for the simulation of the storey response for selected seismic ground motion of predominantly plan-symmetrical reinforced concrete buildings with consideration of the main degrees of freedom were developed. Because the new models are simplified, they were validated for selected frame buildings, frame building with infills and wall-frame building. For nine different analysed buildings, four of which were pseudo-dynamically tested, the pushover analysis and nonlinear analysis can be performed with sufficient accuracy with the simplified nonlinear models. The new models are time efficient and robust. Consequently, they can be utilized for the seismic risk and loss analysis based on a direct assessment of damages considering the results of nonlinear dynamic analysis.
The simplified models of the analysed buildings were utilized for performing the seismic stress tests, which were extended in the reliability domain for the study of the impact of the incomplete building data on the test outcome. Three new reliability levels of the stress test were developed. The proposed stress tests were performed for a contemporary and older reinforced concrete frame building and the results were presented in the form of a seismic certificate based on the seven-level grading system. The grading system considers the probability of building collapse and expected economic losses. The outcome of the stress test for the second and third reliability level was identical to the outcome of the stress test, which was determined with the conventional nonlinear building model. Quite comparable outcomes of the stress test were also obtained for the first level. Therefore, with some additional research, all three levels of the seismic stress test could be introduced in practice.