No abstract

There is a lack of detailed information about wind flow and distribution of wind pressure around atypically shaped high-rise buildings. The national standard EN 1991-1-4 Eurocode 1 used to determine the effects of wind on the territory of Slovakia (and indeed other countries of the European Union) does not have a procedure for determining the effects of wind on objects of triangular shape. This presents a problem for designers and engineers, as there exist no generally binding/valid rules to follow when performing the wind effect analysis. This paper shows the procedure of identification and results of the external wind pressure coefficient for the triangularly shaped high-rise building. Two methods of calculation have been chosen for this purpose. First, experimental measurements were performed on a scaled model of the building cross-section in the wind tunnel. Subsequently, software simulations were performed on the same scaled model in the CFD (computational fluid dynamics) program ANSYS CFX. Results of wind pressure were obtained for two directions of wind flow measured in 16 sampling points distributed irregularly around the circumference of the model. Results were mutually compared and verified. At the end, the wind flow effects on a real-size triangular high-rise building in the built-up area performed by software simulation are shown.

This paper deals with a problem of eigenfrequencies of cylindrical tank (steel water tank). For an ANSYS analysis of eigenfrequencies some numerical models of cylindrical tank are used and finally results got by these models are compared with experimental results in laboratory. In final part of the paper some crucial results are presented both in a graphical and numerical way.

Voided slabs using voids formed by permanent fillers or removable forms have been used in reinforced concrete floor systems for more than 100 years. In this article we will focus on the natural frequency of voided biaxial slabs system Cobiax. Cobiax void former modules are synthetic hollow spheres or rotational ellipsoids mounted in the relevant spaces between the upper and lower reinforcement. We have analyzed the slabs of different thicknesses with adequate void former modules and spans following the manufacturer's recommendations. All models were considered as simply supported slabs. Natural frequencies calculated using simplified analytical methods have been compared with those obtained by numerical methods. Numerical calculation was done using the 2D elements with reduced properties and using the accurate 3D model of a structure.

The paper presents analyses of deformations and stress of the circular rotationally symmetric tanks. The reinforced concrete tanks – water reservoirs – resting on elastic subsoil have been analyzed. The elastic subsoil has been modeled using three basic subsoil models: half-space model, two-parametric model and one-parametric (Winkler) subsoil model. Particular modifications have been applied to the basic models which yield in seven models presented. The cylindrical tank has been analyzed in the interaction with the subsoil, while the elastic subsoil has been characterized by different parameters. The differences in modeling using individual calculation models have been highlighted. The results from analytical and numerical solutions have been presented and compared in graphs and tables. The method for the calculation of settlement of the circular foundation plate was verified experimentally. The settlement of the circular plate was measured while the silo was fully loaded by its contents. The experimentally obtained values have been compared with the calculation results. In the conclusion the recommendations for the suitable model subsoil for these types of structures have been presented.