Befestigungen über Eck unter Zug‐ und Querlast

Behaviour of Anchors Installed Perpendicular to Each Other in Two Faces of a Concrete Element Applications where anchors are installed in two faces of a concrete element perpendicular to each other (e. g. in a corner of a building or a column) and loaded simultaneously in tension or shear are not covered by the well‐known CC‐Method (CCDMethod). In order to investigate the load bearing behaviour tests were carried out. Based on the test results a design method is proposed.     

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.     

Querkrafttragfähigkeit von Fahrbahnplatten ohne Querkraftbewehrung

Es wird über Versuche zur Querkrafttragfähigkeit von Brückenfahrbahnplatten aus Stahlbeton berichtet. Diese zeigen, dass die bekannten Rechenansätze für Bauteile ohne Querkraftbewehrung nach DIN 1045‐1 bzw. DIN‐FB 102 für Fahrbahnplatten auf der sicheren Seite liegen, die tatsächliche Tragfähigkeit aber weit unterschätzt wird. Weitere Ansätze zur Berechnung der Querkrafttragfähigkeit von Stahlbetonbauteilen ohne Querkraftbewehrung werden erörtert. Während die Modelle bei der Auswertung einer Datenbank von Balkenversuchen eine gute Übereinstimmung aufweisen, zeigt der Vergleich mit den Modellversuchen, dass die meisten Rechenverfahren die Tragfähigkeit der Platten unterschätzen. Zur Berechnung der Querkrafttragfähigkeit von Platten ohne Querkraftbewehrung unter Punktlasten wird ein Modell vorgeschlagen, welches die Querkrafttragfähigkeit mit der Zugbeanspruchung der Biegezugzone im kritischen Bereich verknüpft. Shear Resistance of Bridge Decks without Transverse Reinforcement The design of concrete bridge deck slabs is of major concern since the introduction of the Eurocodes as the calculated shear capacity of slabs without stirrups and staggered reinforcement according to the new design standards is often considerably smaller compared to the former regulations i.e. DIN 1045:88. This raises the question whether the existing structures are still save. A series of 12 tests on 4 different specimens representing a bridge deck was performed to examine the real load bearing behaviour of a slab with and without shear reinforcement under a wheel (point) load. The evaluation of the test results revealed, that the current design formula with an assumed elastic shear force distribution leads to rather conservative values of shear capacity for bridge deck slabs. Various approaches for shear design are discussed and the accuracy is checked by means of a shear database and the test results. A new model to calculate the shear capacity is proposed which shows a better agreement with test data than the known approaches.     

Bewertung von komplexen Windlastwirkungen auf die Gebäudehülle

Appraisement of complex wind load effects on the building envelope. The natural wind loading normally dominates the design of building silhouettes in its ultimate limit state. With respect to the static load bearing capacity, simplified load models are available which are accepted and approved. However, for certain situations a more thorough analysis, taking into account more complex loading effects, is meaningful. In the present contribution, it is shown exemplary to which extent the increased modelling effort is worthwhile.