Failure of Slender Concrete Columns Due to a Loss of Stability

Abstract

The European standard for the design of concrete structures that are likely to lose stability requires taking into account the effects of second order theory. This effect increases the impact of a bending moment due to member deformation and additional eccentricity. Slender members can be calculated by the use of a non-linear method. This approach shows a deficit in global reliability for cases where the concrete columns fail due to the loss of stability before reaching the design resistance in the critical cross-sections. Buckling is a brittle failure which occurs without any warning, and the probability of its formation is markedly influenced by the slenderness of the column. Here, the calculation results are presented and compared with the results from an experiment which was carried out in cooperation with STRABAG Bratislava LTD at the Central Laboratory of the Faculty of Civil Engineering SUT in Bratislava. The columns were designed according to the methods stated in STN EN 1992-1-1, namely, a general non-linear method. The focus of this study is to compare multiple approaches based on codes used in Germany (DIN 1045-1, 2001) and Austria (ÖNORM B 4700, 2001) with the present European code mentioned above. The paper aims to compare the global reliability of slender concrete columns with variable slendernesses of 90 and 160.

Probabilistic and Semi-Probabilistic Analysis of Slender Columns Frequently Used in Structural Engineering

“…In addition, details of the column layout and test results of the columns made from C100/115 are also documented in [5,6]…”

“…= e • • (6) where is a constant value and is assumed to be 0.8. The safety index is to be taken in accordance with the target reliability index and applicable standards.…”

“…The general approach described above can be implemented by applying various formats of different intricacies together with their corresponding efficiencies. Recent experimental studies for slender reinforced concrete columns [3] have indicated that the classical design approaches for distinguished N-M combinations are too conservative and so cannot meet the reliability level that is required in current design standards and the desired level of structural safety required in modern societies [4][5][6]. Simultaneously, due to the rapidly developing computational technologies and formats, more sophisticated numerical probabilistic simulations and non-linear calculation formats are becoming more important and finding their way into engineering practice [7].…”

Reliability analysis of very slender columns subjected to creep

“…Researchers from other countries have also studied second-order effects in very slender columns, as can be seen in Strauss et al (2018) and Benko et al (2019). However, in these studies, the emphasis was placed on Eurocode 2 (CEN, 2004) using the global safety factor.…”

Round-Robin Modelling of the Load-bearing Capacity of Slender Columns by Using Classical and Advanced Non-linear Numerical and Analytical Prediction Tools

“…Nonlinear calculations were compared with a series of experimentally verified slender columns. 4,[6][7][8][9] State of the Art "Design of Slender Columns" EN 1992-1-1 10 includes the general method ( §5.8.6), the procedure with nominal stiffness ( §5.8.7) and the method with nominal curvatures ( §5.8.8) hence basically providing three verification methods for the design of slender compressive elements. We believe the results with these three methods should be compared with those proposed in this paper.…”