This paper describes experiences with use of different types of experiments (i.e. loading tests) as well as with use of socalled “Design assisted by testing” method given in the standard “Eurocode 1”. Both these mentioned ways are useful in case of a determination and verification of important design parameters, material properties and load-carrying capacities (in case of different types of stresses, used materials or geometric configurations of designed constructions or their elements and details). In this area, during recent years, large number of miscellaneous loading tests have been performed at the authors’ workplace. Therefore, all presented information and all described experiment results in this article are directly based on solved experimental (and theoretical) research programs carried out at Institute of Metal and Timber Structures at the Faculty of Civil Engineering at Brno University of Technology in cooperation with research institutes and companies in the Czech Republic. Most of all research projects were focused on the load-carrying capacity determination as well as on the knowledge about an actual behaviour and failure mechanisms of steel and steel-concrete structural members and details (recently of members made of FRP or GFRP composite, too), usually in case of verification of either existing or newly designed building or bridge structures.

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The paper deals with the behaviour of steel tubular columns filled by high-strength concrete at compression load. Attention is paid especially to the strength of the used concrete and its effect on the buckling resistance of column. Results of the experimental part of research have shown that increasing of concrete strength is efficient only to a certain extent. It was found in the experimental analysis that the use of concrete class C80/95 has only little effect on increase of buckling resistance as compared with the use of concrete class C55/67. In order to evaluate the efficiency of the concrete strength increasing, a theoretical study was carried out, the results of which are presented in this paper. The paper also discusses the possibilities of using other types of concrete (light-weight concrete or slightly reinforced concrete) with regard to their contribution to improving the bearing capacity and taking into account the production costs of the steel - concrete tubular column.

Several methods for agricultural soil compaction evaluation are known. However, there is a lack of knowledge about a soil elasticity, which could be an important factor for final level of compaction. The paper deals with a possibility of evaluation of soil elasticity using automatic computerized oedometer. A simulation of tractor passing was performed as a part of research focused on the monitoring of soil conditions in vineyards. Cyclic loading test of five loading cycles (loading 300 kPa and un-loading 5 kPa) was performed and vertical deflection was observed, which changed in dependency on change of vertical stress. Course of vertical deformation indicates the ability of soil to relax when the load subsides. The paper presents pilot results, that show good potential of using oedometer for soil elasticity evaluating. Information on the elastic behaviour of soil will make it possible to design and apply means for improving soil elasticity and thus help to mitigate the effects of soil compaction.

Concrete filled steel tubes (CFST) represent a composite building member suitable especially for the construction of columns of a skeleton frame. Filling the steel tube with concrete allows the use of suitable properties of both materials and their interaction. This is very beneficial in a fire exposure, where a circular column has slightly better fire resistance than a square column. In case of an assessment of columns at the ultimate limit state (ULS), a buckling resistance decides. In previous research, it was found that increasing the strength of concrete increases buckling resistance only to a certain extent. The main aim of the article is to show through a theoretical study what benefit the use of ultra-high strength concrete has for buckling resistance of CFST.