ABSTRACT
Currently, at public roads and railway lines numerous renovations are carried out adapting these routes to new terms of use, mainly in terms of increased service loads. For this reason many bridges located on these routes also require immediate modernization and/or reinforcement. The main reason for this is the poor technical condition of bridges and viaducts.
Subject of this article is analysis of the carrying capacity of the historic arch railway viaduct (Fig. 1). The vault is made of bricks on lime-cement mortar. Object was built in 1886 and therefore its historical character had to be included in the modernization project. Viaduct span is 6.00 m, vertical clearance 4.26 m, and the overall width 7.42 m. Side view of arch railway viaduct with vaulted structure before modernization. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315207681/cd556cd4-4dcf-4efe-8e29-56fc67b8bfbd/content/fig350_1.jpg"/>
The main task of the carried out modernization was to bring the viaduct to the technical condition corresponding to the current requirements in order to allow normal (or limited) service. Strength of the brickwork and joints (mortar) were examined experimentally in the laboratory and on the viaduct. The paper presents assumptions for the static-strength calculations of the viaduct that were performed with the use of Autodesk Robot Structural Analysis 2010 program based on the finite element method. Numerical model of the viaduct was also presented and selected results of numerical calculations have been presented. Two- and three-hinged models of arch were analysed. Axial forces, bending moments, displacement and normal stresses generated from numerical analysis have been discussed in the article. Maximum vertical deflections of viaduct amounted to 13 mm and occurred in the arch crown (Fig. 2a), while the largest bending moments were located in quarter points of an arch and did not exceed 90 kNm/m (for a three-hinged arch – Fig. 2b). The maximum axial force amounted to -593 kN/m (compression in support nodes) and normal stresses were at the level of 3 MPa (quarter points in the arch). Conditions of the load capacity of the viaduct due to compression and shearing have been met. Load capacity of an arch of the viaduct was determined and proved to be sufficient for the administrator of the railway. At the end modernization scope of the viaduct has been proposed, especially in terms of material and technology. Diagrams from standard load for a three-hinged arch: a) structure deflection and b) maximum bending moments. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315207681/cd556cd4-4dcf-4efe-8e29-56fc67b8bfbd/content/fig350_2.tif"/>
