Abstract:The article handles potential approaches to design and determination of total load capacity of foundation slabs and floors. The research is focused on punching shear failure of reinforced ground supported slab. The article presents detailed results of the experiment made and advanced numerical modelling based on nonlinear analysis and application of fracture-plastic model. The experiment made included a 2.0 9 1.95 m reinforced concrete slab-on-ground of 120 mm thickness. The experiment was followed by a parametric study of total load capacity calculation with nonlinear analysis which is supplemented by calculations based on existing design model code.

IntroductionThe use of steel fibre-reinforced concrete for foundations or industrial floors is a typical example. In these cases, the design encompasses many input parameters that significantly influence the results. The basic requirements to optimize the design include in particular a detailed understanding of the properties of the materials used. This is especially important in the case of complex design situations and the use of advanced numerical simulations. In these cases, it is necessary to describe the material properties in a comprehensive manner. A typical case is fibre-reinforced concrete. Fibre-reinforced concrete exists in a number of variants which differ in the materials used and the shape of fibres [20]. Common problems include the fact that experimental programmes and testing focus on the properties and testing of the selected material [21]. This hinders the creation of advanced material models for the numerical simulation of the actual behaviour. This is especially the case of nonlinear analysis and the finite element method which requires a detailed computing model and a more comprehensive description of the actual material behaviour. During plane and space problems, a general state of stress emerges. It is also necessary to describe and model the damaged material. This is used to describe concrete fracture mechanics [22]. The juxtaposition of specialized tests often creates questions, thus comprising the research space for a more comprehensive description of the material properties.With regard to the research project and the goal of a comprehensive description of the material properties of steel

Some foundation structures can be loaded with horizontal stress, for example pre-stressed foundation structures or structures on undermining areas. Then it is necessary to solute their effects, because they can have very significant effect on the building. When it is spoken about the foundation structures which are loaded with horizontal stress then it is spoken about two possibilities of this loading. In the first case there are horizontal deformations in the structure and in the second case these deformations can arise in the subsoil. In both of them it can be used the method with using sliding joint to increase of shear stress between foundation structure and subsoil. Asphalt belt is often used to create this sliding joint. At the faculty of Civil Engineering some materials are tested to better knowledge of asphalt belts properties and to more precise design and calculation of sliding joint.

Use of a sliding joint is an effective method to decrease the stress in foundation structure where there is a horizontal deformation of subsoil (areas afflicted with underground mining) or horizontal deformation of a foundation structure (pre-stressed foundations, creep, shrinkage, temperature deformation). A convenient material for a sliding joint is a bitumen asphalt belt. Experiments for different types of bitumen belts were undertaken at the Faculty of Civil Engineering - VSB Technical University of Ostrava in 2008. Since 2011 an extension of the 2008 experiments has been in progress and the shear resistance of a slide joint is being tested as a function of temperature in a temperature controlled room. In this paper experimental results of temperature dependant shear resistance are presented. The result of the experiments should be the sliding joint shear resistance as a function of deformation velocity and temperature. This relationship is used for numerical analysis of stress/strain relation between foundation structure and subsoil.

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