Experimental Verification of Fatigue Resistance of Assembly Joints of Truss Main Girder of Temporary Footbridge

摘要

The paper is focused on the problems of the actual fatigue resistance of assembly joints of the temporary footbridge for pedestrians and cyclists, which is being newly developed within the framework of the applied research project of the Technological Agency of the Czech Republic. The necessity of the development of a new temporary footbridge has been invoked by the lack of such constructions in a practice, both in the case of flood situations, and also as the site facilities, for pedestrian traffic crossing on the construction sites of bridges or other structures. Within this work the attention is mainly paid to the static and structural design, in particular to the harmonization of aspects of static solution and structural detailing, to achieve the efficient design. In parallel, two types of the footbridge are being developed, both ones with a lower deck, truss main girders and bracings. The first structure, so-called "short footbridge" with a very small self weight, can reach up to 18 m span; the second structure, "long footbridge" with a normal self weight, can reach up to 36 m span. This paper deals with some problems of the long footbridge fatigue and mainly presents the basic information on the actual behaviour of assembly joints of the structure, if subjected to the fatigue loading actions. The content of the paper is focused on the experimental verification of fatigue parameters of the most important structural details and joints. Within the framework of experimental programme, the fatigue tests of exposed details and joints of the truss main girders have been performed. In this paper, the performance of fatigue tests including elaboration and evaluation of their main results are presented.