Bauzeit und Baukosten für Stahlbetonarbeiten – Berechnungsmethoden und Anwendung

Construction Time and Cost of Reinforced Concrete Works – Calculation Methods and Application Construction time is of crucial importance when it comes to utilizing the production factors in an effective and efficient way. Construction periods that are too short usually result in higher cost, poorer quality and a larger number of disputes. This paper sets out to demonstrate the calculation of construction time whilst considering key construction management parameters. Beyond a simple, deterministic method, other options for calculation are shown that rely on probability calculus. The approaches described to determine construction time and cost are illustrated by a building project example. The deterministic method results in one value per each calculation process (calculation mode 1). In calculation mode 2, probability calculus is applied in a simple fashion. Both range and probability of occurrence can be considered for the relevant input variables. For the third calculation mode, the Monte‐Carlo method is applied using the @RISK software. For each of the parameters to be determined, this method shows a probability distribution.     

Einfluss der Zugspannungen auf das Beulverhalten eines Beulfeldes unter mehraxialer Beanspruchung – Nachweis nach DIN EN 1993‐1‐5, Abschnitt 10

Influence of tension stresses on the buckling behaviour of slender panels subjected to multiaxial stress – Verification according to DIN EN 1993‐1‐5, chapter 10. In DIN EN 1993‐1‐5 according to the reduced stress method multiaxial stress states are already considered in the determination of the single plate slenderness. The interaction curves according to DIN EN 1993‐1‐5 [1] therefore allow for a systematic utilisation of the favourable effect of tensile stresses on the buckling behaviour. However, studies to justify this beneficial effect are missing. Therefore, experimental and numerical investigations have been conducted to give an insight in the buckling behaviour of multiaxially loaded plates. Six tests on isolated steel plates were realized and are presented giving an insight into the buckling behaviour of multiaxially loaded panels. The recalculations of the above mentioned experimental investigations were performed showing an appropriate agreement between the experimental and the numerical results, so that numerical recalculations of the tests confirmed the experimental observations and the applied procedure for conducting the numerical investigations can be regarded as validated. For the realization of the parametric studies, simplified models are generated considering several kinds of boundary conditions. Based on the presented parametric study a new design proposal has been developed and compared to the numerical results showing good agreements for the investigated load cases justifying the utilisation of positive effects from tensile stresses.