Consequences of Simplifications in Modelling and Analysis of Masonry Arch Bridges

Abstract

The paper presents a problem of a simplified modelling of masonry arch bridges utilising a linear elastic material model. Although, such approach provides significant time and labour savings, it may lead to dangerous overestimation of the load carrying capacity of evaluated structures. Theoretical bases for this effect are being explained and illustrated by means of a comparison of two essentially different approaches to analysis of masonry arch bridges. Both of them are using Finite Element Method, however each with different material model for the arch barrel. One of them is based on an advanced nonlinear non-tensile-resistant constitutive model most properly representing masonry, while the other one is a linear-elastic model with unlimited compressive as well as tensile strength. In a parametric study of bridges with various geometries and mechanical properties all differences depending on the applied material model in the structures’ response to typical loading scenario are presented. Clear measures enabling numerical comparison of the approaches are given. Some diagrams are provided to describe and explain effectively the essence and causes of the appearing differences (including distribution of internal forces or cracking development) originating from the chosen material modelling techniques. General conclusions coming from the study are drawn.