Load Carrying Capacity of Metal Dowel Type Connections of Timber Structures

This paper deals with the load-carrying capacity calculation of laterally loaded metal dowel type connections according to Eurocode 5. It is based on analytically derived, relatively complicated mathematical relationships, and thus it can be quite laborious for practical use. The aim is to propose a possible simplification of the calculation. Due to quite a great variability of fasteners’ types and the connection arrangements, the attention is paid to the most commonly used nailed connections. There was performed quite an extensive parametric study focused on the calculation of load-carrying capacity of the simple shear and double shear plane nail connections, joining two or three timber parts of softwood or hardwood. Based on the study results, in conclusion there are presented simplifying recommendations for practical design

Stiffness of Carpentry Connections – Numerical Modelling vs. Experimental Test

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]

Optimisation of Transversal Disposition of Steel and Concrete Composite Road Bridges

AbstractThe paper deals with optimisation of transversal disposition of steel and concrete composite road bridges in terms of the number of steel beams. For this purpose, a parametric study was performed, in which a total of 32 superstructures of steel and concrete composite road bridges, with different number of steel beams, different road widths and theoretical spans, were modelled and assessed. The reliability verification of the superstructure has been done according to Eurocodes. A result of parametric study is a comparison of advantages of the double-beam and the four-beam variants in terms of material consumption when considering different transverse dimensions and spans of the bridge. The individual variants are compared on the basis of the consumption of structural steel, concrete and reinforcing steel bars

NSS test of structural steel corrosion

Corrosion of structural steel represents one of the most significant degradation effects on the reliability and durability of steel bridges. Relevant data needed for good protection of steel structures can only be reliably derived from long-term measurements. For acceleration of corrosion process, measurement in the corrosion chambers can be utilised. The article summarized the results of experimental measurements of corrosion losses carried out on 30 specimens of structural steel corrosion in the test chamber during 140 days. The environment in the chamber simulates the conditions in which, generally, several-day period in the chamber corresponds to either months or even years of outdoor exploitation. Discussion focused on the results interpretation to corrosion progress in real conditions is given, as well. The obtained measurement data should be used to refine the input data for corrosion maps in Slovakia. The presented results are part of a research project focused on measuring corrosive losses of structural steel in situ and as well as in laboratory conditions

Real Stiffness and Fatigue Resistance of Stringer-to-Cross-Girder Connection of Riveted Steel Railway Bridges

Steel girder bridges with member decks belong to the most frequently used types of superstructures of old riveted steel railway bridges. During their service life, the bridge deck members are affected by escalating effects of the traffic loads that significantly exceed those for which they were originally designed. As a result, these structures are often subject to the increased effects of fatigue degradation. One of the typical cases of fatigue damage on steel riveted bridges is a fatigue crack in the web of the stringer at the point of its connection to the cross girder. Such a connection used to be considered to transmit the axial and shear forces only, and so no fatigue crack was expected to develop in this detail during the bridge service life. However, the relatively frequent occurrence of fatigue cracks indicates the incorrectness of this assumption. This article is divided into two parts. Firstly, the bending stiffness of the stringer-to-cross-girder connection with different structural arrangements is analysed. Theoretical and experimental analyses of fictitious steel superstructures as well as of a real superstructure of an existing steel riveted bridge were performed to clarify the real stiffness behaviour of this detail. The results of the analyses confirm the assumption of a certain bending stiffness of the observed connection. Subsequently, attention is paid to the fatigue resistance of the riveted stringer-to-cross-girder connection in terms of the use of European standards. The results of fatigue tests performed on specially prepared test samples are presented with the aim to define the fatigue detail category

Reconstruction of the Bridge Over the Hron River in Village Hronovce

The paper deals with the reconstruction of four-span bridge carrying the third-class road over the Hron river nearby village Hronovce. The need of immediate reconstruction of the bridge object was evocated by an accident of the middle pier. The reconstruction consisted of two phases: the sanitation of the substructure and the replacement of the original superstructure, which was in bad technical condition. This paper deals mainly with the second stage, e.g., the design of new superstructure, which was suggested as a continuous, three-span steel and concrete composite structure

Analysis of the Stringer-to-Cross-Beam Riveted Joints Behaviour

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