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  • Author: Josef Vičan x
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Abstract

Verification of beam-column resistance can be accomplished according to design approaches given in EN 1993-1-1 []. These approaches are derived from verification of single span beam with pinned end conditions subjected to compression and bending moments. In the case of different end conditions, the application of those approaches is not so accurate and more difficult. Therefore, the comparison of verification according to above standard EN 1993-1-1 [] as well as EN 1999-1-1 [] to results of experimental analyses of beam-columns having pinned-fixed end conditions subjected to an eccentric compressive force simulating the behaviour of columns integrated into frames is presented in this paper.

Abstract

The main aim of the paper is to present results of the numerical and experimental studies related to the analysis of the real stiffness of the stringer-to-cross-beam connection in order to avoid approximation of this joint by means of complicated 2D modelling and to use simplified 1D model for global analyses of bridges with open bridge decks.

Abstract

In the paper, the actual condition of several existing concrete railway bridges with encased steel beams is discussed. This structural type represents relatively often solution for small span railway bridges in Slovakia. The main conclusions from inspections and in-situ diagnostics are published together with the results of the loadcarrying capacity calculation on the basis of new European codes. Despite of well-known disadvantages, the bridges with filler-beam decks are still demanded by railway authorities because of their big stiffness and small construction depth.

Abstract

The article describes general principles and basis of evaluation of existing railway bridges based on the concept of load-carrying capacity determination. Compared to the design of a new bridge, the modified reliability level for existing bridges evaluation should be considered due to implementation of the additional data related to bridge condition and behaviour obtained from regular inspections. Based on those data respecting the bridge remaining lifetime, a modification of partial safety factors for actions and materials could be respected in the bridge evaluation process. A great attention is also paid to the specific problems of determination of load-caring capacity of steel railway bridges in service. Recommendation for global analysis and methodology for existing steel bridge superstructure load-carrying capacity determination are described too.

Abstract

In this paper, numerical modelling of the traditional carpentry connection with mortise and tenon is presented. Numerical modelling is focused on its stiffness and the results are compared to results of experimental tests carried out by (Feio, 2005) [6]. To consider soft behaviour of wood in carpentry connections, which are related to its surface roughness and geometrical accuracy of the contact surfaces, the characteristics of the normal contact stiffness, determined experimentally, are introduced in the numerical model. Parametric study by means of numerical modelling with regard to the sensitivity of connection stiffness to contact stiffness is presented. Based on the study results, in conclusion there are presented relevant differences between the results of numerical modelling and experimental tests (Feio, 2005) [6].

Abstract

The following article discusses the problem of durability of girders made of structural steel S355 affected by corrosion. It presents the Polish procedure for calculating the time between failures of steel elements of bridge and durability factors necessary to estimate the impact of corrosion on the durability of steel road bridges. According to the presented procedure, two real bridges of steel structure were analysed. The bridges selected for analysis are located in extremely different corrosive environments in Poland. This bridges were built in different areas of the country which are characterized by different (mountain, urban) aggressiveness of the environment. The objects of the analysis differ in terms of corrosion type occurring on the bearing system. Their age is also different which has a significant impact on their safety.The results obtained allowed to determine the time when, with the existing corrosion damage, failures may occur.