University of Patras, Department of Civil Engineering
In the present paper a study on the strengthening of a small byzantine church damaged by earthquakes is presented. The existence of vaults and the dome make the byzantine churches vulnerable to seismic actions, while the frescoes restrain the application of some strengthening techniques. Herein emphasis is given to the numerical investigation of the effectiveness of retrofitting measures which on the one hand, do not alter the interior surface of the structure and on the other hand reduce the stress state of both the vaults and the pendentives. These measures are a) a setup of diagonal tendons at the level of the springs of main vaults, b) surface-bonded Aramid Fibre Reinforced Plastic sheets (AFRP) at the extrados of both the main vaults and the pendentives, and c)bonding of AFRP sheets at the extrados of all the vaults of the church and the pendentives too. A failure criterion for masonry under biaxial stress state is used for the assessment of the aforementioned strengthening techniques. It is proved that the poor diaphragm action provided by the tendons is unable to improve the stress conditions of the parts at higher elevation but the bonding of AFRP sheets at the extrados of main vaults and pendentives is efficient even at the corner bays, whereas if AFRP sheets are additionally bonded to the vaults of corner bays, no more improvement tomain vaults can be achieved.
masonry, strengthening, vaults, AFRP, damage, church