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Abstract: Load bearing behaviour of combined steel pile walls under water pressure under the influence of positional imperfections. Increasing global trade leads to a significant expansion and strengthening of seaport facilities and thus to an increasing use of quay walls with combined steel pile walls. Horizontal loads, which mainly come from groundwater pressure, are forwarded by Z‐shaped intermediate piles via special connector profiles to I‐shaped king piles and then directed into the ground. The design of the intermediate piles is regulated in DIN EN 1993‐5. The test‐based method in provides the most accurate and thus most economic results. This paper shows how with this method water pressure resistances were derived for the HZ‐M/AZ‐system [2] in nominal position. However, fabrication influences often lead to deviations from the nominal position, which the intermediate piles have to compensate for. In this paper, the influence of a stretching of a sheet pile wall in the wall direction and thus an increase of the system width is examined. Firstly, the stretch itself is analysed and secondly, the load bearing behaviour of the stretched system is compared to that of the system in the nominal position. [ABSTRACT FROM AUTHOR]

Abstract: Applying the theory of structural state of stress, this paper investigates the behaviour characteristics of concrete‐filled stainless steel tubular (CFSST) short columns during their experimental working process. First, the sum of the generalized strain energy density (GSED) values (Eij) of the short column at every load value (Fj) is normalized as Ej,norm to describe the structural state of stress. Then, the state of stress jump is identified by applying the Mann‐Kendall (M‐K) criterion to the Ej,norm‐Fj curve creatively, following the rule of quantitative change to qualitative change. The investigation reveals the general state of stress mutation characteristics of short columns at specific individual loads, leading to an update of the failure load. Furthermore, it is verified that the simulative working behaviour of short columns can also reflect the state of stress characteristics revealed through the investigation into the experimental data. Hence, we formulate the relationship between the failure loads of CFSST short columns using the simulative data, and then validate it through both experimental and simulative data. In total, this study explores a new way to reveal some unseen working characteristics of structures; hopefully, it will initiate similar research on various structures, and the results achieved will lead to more rational design codes. [ABSTRACT FROM AUTHOR]

Abstract: Equivalent initial imperfections for applying the partial internal forces method for flexural buckling about the weak axis. This paper compares design approaches for equivalent initial imperfections of steel members with hot‐rolled double symmetric I‐/H‐profiles subjected to buckling about the weak axis. In addition to the normative rules applied in Germany and Europe, design approaches for imperfections are also taken into account, which are currently discussed as part of the further development of Eurocode 3. A proposal using the partial internal forces method allows a consistent design for steel members taking into account the cross‐sectional failure as well as the flexural buckling about the strong and weak axis. The proposal leads to design results that agree well with the results of numerical simulations. [ABSTRACT FROM AUTHOR]

Abstract: Dedicated to Prof. Dr.‐Ing. habil. Joachim Lindner on the occasion of his 80th birthday This paper reports the latest developments concerning the application of Generalised Beam Theory (GBT) to thin‐walled members with deformable cross‐section and whose undeformed axis is a circular arc, with no pre‐twist. Initially, the fundamental equations and relations are presented, leading to the first‐order equilibrium equations and associated boundary conditions, which can be written in terms of GBT modal matrices or stress resultants. Then, the procedure to obtain the cross‐section deformation modes is explained. Arbitrary (open, closed or ”mixed“) flat‐walled cross‐sections are covered, even though the kinematic constraints employed to subdivide the modes are much more complex than for prismatic members – in particular, the mode shapes become dependent on the curvature of the beam axis. Using a displacement‐based GBT finite element, a set of illustrative examples is presented, involving complex local‐distortional‐global deformation. These examples show that very accurate results are obtained with the proposed GBT formulation and that the modal solution provides in‐depth insight into the structural behaviour of naturally curved members. [ABSTRACT FROM AUTHOR]

Abstract: Trough girders are widely accepted in engineering on account of lowing construction depth and protection against traffic noise pollution, but most of them are used for simple‐supported girder bridges with a span of generally less than 30 m. On the railway line of Nanjing–Qidong in China a new railway bridge will be built which has a span of over 64 m but a construction depth of less than 2.4 m on which Shanghai–Nantong railway line is also passed, so the type of concrete‐filled steel tube tied‐arch bridge with trough girder was chosen. For such a new structure hardly used in engineering, there are no research results yet available about mechanical properties of the structure. This paper therefore makes for the bridge an experimental model of 1:4 geometric scale in order to test mechanical properties under operation load, cracking load, and ultimate load such as cracking diagram, load‐carrying capacity, stress distribution, and failure mechanism. According to the experimental results, when the model is subjected to longitudinal bending moment, the failure mode is similar to that of pure bending of a girder, and when the model is subjected to transverse bending moment failure mode behaves like the flexural failure mode of the traditional reinforced concrete structure. A non‐linear element analysis is also made on the model with the results in good agreement with that of the experiment. The same modeling method is applied to the finite element analysis of the real bridge, considering various load in design. In the analysis, it is finally verified that this new type of bridge meets specification requirements in strength, rigidity, and resistance to cracking. [ABSTRACT FROM AUTHOR]

Abstract: Failure of a steel pallet rack in Athens. Pallet racking systems have peculiar characteristics which differ from usual steel structures that make them sensitive to stability failure modes. In the present paper a rack failure is presented where the rack has failed due to lateral torsional and distortional buckling of its most stressed uprights. The structural behavior was studied by a combination of experimental and numerical/analytical methods. The investigations included test loading, bending tests on pallet beams, compression tests on stub column and bending tests on beam end connectors. Subsequently, a global geometrical non‐linear analysis is performed on the 3‐D system. Its results indicate by comparison with the pictures of the actual structure that the collapse mode is correctly detected. Conclusions are drawn that recommend the performance of static and dynamic analyses on an obligatory basis. [ABSTRACT FROM AUTHOR]