This paper presents the negative effects of the vibrations produced by railway transport systems upon the constructions in the neighbourhood of the railways. The railway vehicles in motion produce very high intensity vibrations. Through the soil, these vibrations are transmitted to the foundations of the constructions in the vicinity and consequently settlements, cracks, even collapses of buildings can occur. The paper contains a theoretical part where the features of free and forced vibrations of the track/vehicle system as well as the features of the vibrations of the vehicles displacing along a joint track are described, followed by a practical part in which are shown the results of measurements made to highlight the effects upon the constructions (values of accelerations, velocities and displacements).

In this paper several aspects regarding the dynamic behaviour of the steel footbridge structures under the action of the loads generated by the pedestrians’ displacement, correlated with the traffic comfort of the pedestrians crossing the structure are presented. The crossing pedestrians’ comfort criterion requires the values of vibration frequencies and accelerations of the structures in certain limits so that the vibration amplification or resonance is avoided. The paper takes under investigation eight footbridges on steel, composite steel-concrete girders and a cable stayed structure from the viewpoint of frequencies in vibration Mode 1 in a vertical plane, generated by their own weight - natural frequency, or from a partial pedestrian loading, as well as the resulting resonance risk and the traffic comfort.

The term of shear lag is related to the discrepancies between the approximate theory of the bending of beams and their real behaviour. It refers to the increases of the bending stresses near the flange-to-web junctions and the corresponding decreases in the flange stresses away from these junctions. In the case of wide flanges of plated structures, shear lag caused by shear strains, which are neglected in the conventional theory, may be taken into account by a reduced flange width concentrated along the webs of the steel girders. In EN 1993-1-5, the concept of taking shear lag into account is based on effective width of the flange which is defined in order to have the same total normal force in the gross flange subjected to the real transverse stress distribution as the effective flange subjected to a uniform stress equal to the maximum stress of the real transverse distribution. Some aspects concerning the shear lag phenomenon and a working example for a box girder of a heavy crane runway to illustrate the determination of the shear lag effect are also presented.

Abstract. Having a remarkable appearance, conoid type surfaces have frequently been used in architecture and constructions. Conoids are part of the category of ruled surfaces. The representation of this kind of surfaces can be performed with one of the following representation systems: orthogonal projection on two planes of projection (Monge projection), axonometry, projection with elevations. The present paper focuses upon the generation and projection with elevations of three types of conoids, namely the Plücker, the Küper and the Viviani conoids

This paper presents several theoretical issues regarding the behaviour and calculus of the connections made with end plates and bolts, including the cover plate for the tensile stress flange. An example for calculating the hybrid connection solution is also provided, when end plates are joined together with bolts and an additional cover plate over the joint area, at the elongated flange of the girder, a solution applied for a bridge for which the feasibility study was performed.