Stone Masonry Arch Bridges: In situ Testing and Stability Analyses by Using Numerical Methods; Examples from Hungary

Abstract

Maintenance and restoration is a common problem of historical stone structures. To control the stability and to verify the load-bearing capacity of these structures there are several modelling methods from the simple approximate calculations to the difficult numerical methods. Several Hungarian stone masonry arch bridges were investigated in the past few years. It was experienced that it is difficult to determine adequate input parameters for the numerical modelling from the in situ tests even for the simplest methods for instance trust line analysis and rigid block method. The modelling methods are able to describe the behaviour of the stone masonry arches but the results are depending on the quality of the input parameters, which are determined by the diagnostic tools. The analysis of these structures becomes more difficult since they are under protection for their historical value. The paper focuses on the most important in situ diagnostic methods of the stone masonry arch bridges according to different examples from Hungary. The investigated bridges have different stone materials (sandstone, andesite tuff) and different structures (single-span, multi-span). The applications and limitations of these diagnostic methods are also described. The paper also includes parametric analysis of the different input parameters of modelling such as the quality of the stone material (weathering, water content), strength of the blocks, shear strength between the blocks, quality of the joints. The aim of this research is to bring closer the numerical methods to the practice and develop the diagnostic methods to provide adequate information for the effective modelling.