János Krähling

A methodology for the development of historical building archetypes for seismic performance assessment

The probabilistic estimation of the magnitude of historical earthquakes requires the analysis of actual building structures affected by those earthquakes. The analysis complicates because most of these buildings no longer exist or were greatly modified, present a great variety of features and the number of analysis for probabilistic assessment is high. As it is not practical to analyze all structures, an alternative is to use structural archetypes representing the affected buildings. This paper presents an approach to develop a quantitative framework for the generation of historical archetypes. The method is illustrated via the definition of a specific archetype for the study and assessment of the effects of the 1763 Komarom earthquake. The historical survey of Tata, Hungary, is assumed as representative of the region and one historical building is utilized to illustrate the archetypes evaluation process.

The Ottoman Sultan’s Albums at Budapest University of Technology and Economics

In the nineteenth century, the Ottoman empire’s large-scale development was illustrated by the new medium of photography. Different territories of the empire were photographed and Ignac Alpar, a significant architect of Hungarian Historicism, purchased some of these photographs. Alpar’s interest in oriental art derived from the ideology of Turanism believing that a Hungarian national style could be developed with the use of oriental motifs. One of the photographs (‘Tombs of Mamluks, Cairo’) of the collection provides some evidence of this idea. The essay develops the background and evidence for the Hungarian-oriental relationship at the turn of the nineteenth-twentieth century.

Fragility Estimation and Comparison Using IDA and Simplified Macro-Modeling of In-Plane Shear in Old Masonry Walls

The estimation of fragility functions associated with dynamic structural analysis provides the probability of a certain damage state given an intensity measure. The presented paper discusses this technique regarding its application to a method to estimate the magnitude of historical seismic events relying on the behavior and damage in real historical structures. A bin of 50 seismic records is selected matching the Komarom hazard spectrum and applied with Incremental Dynamic Analysis to generate the damage state points of a 2D one-story frame numerical model developed using Opensees code and calibrated to simulate the in-plane shear behavior of historical old clay and adobe masonry infilled walls. A scaling technique is applied and a damage type identification strategy adapted to the material model are developed to perform Incremental Dynamic Analysis and efficient fragility function fitting in MATLAB. Results highlight considerable uncertainties regarding the calibration of the numerical model, material and geometric nonlinearities and seismic record selection in this procedure. Despite efficiency, the methodology application and overview suggest that a full probabilistic approach fragility function fitting using the background of seismic hazard analysis and reliability theory, providing a concomitant sensitivity analysis, is important to proceed with variables weight evaluation and account for uncertainties.