Use of distinct element method in the assessment of earthquake behavior of masonry structures

Abstract

There are a number of masonry structures in Istanbul and in other cities of Turkey that suffered severe damage from earthquakes. As they will continue to get affected by the earthquakes, more research is needed to assess their seismic dynamic behavior particularly in the states of large deformations/damage and collapse. This still remains as a challenge in spite of significant developments in understanding factors affecting the seismic resistance of masonry structures. The present thesis deals with non-linear dynamic analysis of masonry structures modelled through distinct element methodology. First, a masonry mosque has been built at 1:10 reduced scale and tested by subjecting it to a sequence of earthquake excitations on the shake table in three phases: test of the base-isolated model, of the model as it is and that of the strengthened model. The results of these three phases were used in the calibration/validation of the numerical model developed by distinct element approach. It has been concluded that the methodology and the elements developed in this stage are good enough to be employed in the investigation of real masonry structures. In the second stage, three masonry minarets in Istanbul were studied under sine waves (velocity amplitude range: 10 cm/s – 100 cm/s; frequency range: 0.1 Hz – 13 Hz) and under real and simulated earthquake ground motion. The deformation levels and patterns induced in the minarets and the energy balance in the system are investigated to analyze the damage processes.