Influence of deformation at a heritage building support on stability of groined masonry arch

Abstract

Masonry arch stability criteria definition has been developed by numerical modeling of cracked arch shell structure of Riga cathedral. Settlement of supports induced strains in masonry arch shells which lead to stress redistribution and crack forming in masonry shell structures is serious problem for heritage buildings. Deformation criteria should be developed for safety exploitation of heritage masonry structures. The main task of the present research is - developing deformation criteria for evaluating of masonry shell construction stress-strain state. Three-dimensional scanning of arch structure by means of Leica 3D laser scanners were used to determine geometric model of masonry arch shell.
Previously accomplished monitoring data was used and a new monitoring program was developed to define unequal settlements of supports. The settlements monitoring of Riga cathedral supports and numerical modeling to define settlement inequality were used as initial information to compare computer modeled deformed structure shape with existing cracked masonry structure. Geodesic monitoring by optical tools and mechanical tensometers have been used for determination of a crack expansion since 2005. Twenty one Optical Fiber Sensors of SOFO type are used now to measure deformations to establish safe exploitation limits. Multilevel analysis of masonry shell has been fulfilled by finite element software and applied for developing safe exploitation criteria.