The objective of the studz presented in this paper is to investigate the effects of masonry infills on the shear demand and failure of columns for the case when reinforced concrete frames with such infills are modeled by means of simplified nonlinear models that are not capable of the direct simulation of these effects. It is shown that an approximate simulation of the shear failure of columns can be achieved through an iterative procedure that involves pushover analysis, post-processing of the analysis results using limit-state checks of the components, and model adaptation if shear failure of columns is detected. The fragility parameters and the mean annual frequency of limit-state exceedance are computed on the basis of nonlinear dynamic analysis by using an equivalent SDOF model. The proposed methodology is demonstrated by means of two examples. It was shown that the strength of the four-story and seven-story buildings and their deformation capacity are significantly overestimated if column shear failure due to the effects of masonry infills is neglected, whereas the mean annual frequency of limit-state exceedance for the analyzed limit states is significantly larger than that estimated for the case if the shear failure of columns is neglected.
COBISS.SI-ID: 6102113
In the paper, a preliminary version of the methodology for determination of default dispersion measures for seismic response of RC frames is developed. In order to reduce the computational work, a simplified two-step procedure for determination of dispersion measures is proposed. In the first step, statistical characteristics of global system parameters are determined by means of nonlinear static (pushover) analysis and consecutive idealization of pushover curves. In the second step, total dispersion of response is determined by Incremental Dynamic Analyses (IDA) for a group of equivalent SDOF systems and a group of ground motion records. The characteristics of SDOF structural models are generated based on the data from the first step. The effectiveness of the proposed approach and recently developed practice-oriented approach for probabilistic seismic assessment of building structures is tested on the selected results of a four storey building. Good agreement between the results obtained by both simplified approaches and results obtained by more "accurate" procedures is observed.
COBISS.SI-ID: 6064481
The results of an experimental programme aimed at analyzing different types of testing in plane seismic response of masonry walls, are presented. A series of six identical masonry walls with dimensions 100/100/30 cm (length/height/thickness), built from modern hollow clay masonry units and thin layer mortar in bed joints have been tested by subjecting the walls to cyclic lateral load. Walls were tested using three different boundary conditions. The first one is a cantilever type with only prescribed lateral displacements at the free end. The second one has fixed rotations and vertical displacements at both ends, while the third one has fixed rotations at both ends and fixed (constant) vertical compressive load. The response and failure mechanism as well as limit states, deformation and resistance capacities are presented and compared.
COBISS.SI-ID: 1915495