The Approach Slab Experiment - Design and Set up of the Experiment

Abstract:

The paper deals with experimental program concerning transition zone of road bridges with the use of approach slab. The experimental setup was constructed in the laboratory of the Slovak university of technology in the scale 1:2.The main function of the approach slab is to ease the transition from stiff foundation of the abutment to an embankment with much less stiffness. As a part of the transition zone, the slab helps to overcome different stiffness of the foundations. Good design of the approach slab and also the transition zone improves the transit of vehicle and enhances the comfort of the vehicle driver.Main goal of the experimental program is to observe the change of the structural scheme of the approach slab throughout the time via bedding stresses under the slab supported by the gravel soil, and also via the supporting forces in the connection to the abutment. The deflection of the slab is observed to confirm the slab behaviour. The possibility to observe all necessary variables with the option to adjust the height of the slab connection is provided by special construction modifications of slab to abutment joint.Due to the fact, that leading variable loading of the approach slab is traffic, loading of the specimen will be cyclic. This loading type causes dynamic response not only of the approach slab, but also of the experimental setup. Part of the experimental setup design is preliminary numerical, time depended analysis of the experiment. On the basis of results of the preliminary analysis the strain of members of experimental setup was checked to maintain the safety of the experiment during whole time. The analysis also shows predicted behaviour and strain of the approach slab, etc.