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Abstract

The interaction of piles with different lengths and the grillage in the foundations of high-rise buildings is considered. The numerical modeling of the «base - foundation - superstructure» system is performed. The redistribution of the efforts in piles depending on the sizes of a foundation slab and the parameters of piles (length and location) is investigated. Typical zones of a foundation such as central, lateral, and angular ones are separated. The redistribution of efforts between piles and a grillage is revealed.

Abstract

The carrying structure of the bridge over the Jiu River at Aninoasa consists in two parallel concrete arches with variable height of the cross section, sustaining a concrete deck through vertical concrete hangers. In the time period passed since the bridge was erected, some structural elements shown damages. In order to establish the technical state of the bridge, a technical appraisement was performed and according to this, the most exposed elements to the risk of failure are the hangers.

The purpose of this paper is to present briefly both, the method used to test the actual bridge carrying capacity in situ and the finite element model developed for the static and dynamic analysis of the structure.

In order to estimate the state of the structural elements, two ways were followed. In the first stage, a test project was carried out and in the second stage, a complete 3D finite element model was developed to analyze the bridge structure.

The test project has foreseen the loading of the bridge by heavy unloaded trucks, disposed in some positions on the deck and the measurements of the deck and arches displacements. The positions of the trucks were established in order to obtain the maximum values both for arches transverse displacements and vertical displacements of the deck. Using electro-resistive transducers the hangers elongations and strains values on their cross section were also measured. These measured values were compared with those obtained from the numerical calculations performed by using the complete finite element model. By means of the finite element model, also the response of the structure following the dynamic action of vehicles was investigated.

Abstract

Road bridges with steel arches are used efficiently for medium and large spans. These solutions show advantages determined by the arches geometry, by the number and distributions of hangers and by the form and type of the arches bracing system.

The appearance of the welding as standard connection procedure for steel bridges, for road bridge decks two solutions are mainly used:

- the solution with a concrete slab acting together with the stringers and cross beams (the composite solution);

- the solution with orthotropic deck (the orthotropic deck consists in a network formed by the continuous longitudinal stiffeners and cross beams connected at the upper part by a steel plate).

In this paper a comparative study of the strength and fatigue checks performed on the new road bridge over river Argeşel near Mioveni in Argeş county is presented. The results are obtained using the Romanian standards STAS 1844-75 and SR 1911-1998 and the European norms SR EN 1990, SR EN 1993 and SR EN 1994. The deck was designed with two parallel steel arches, which are sustaining through vertical hangers a concrete slab connected with steel girders at the way level.

The aim of the paper is to outcome the safety factors obtained from checks performed on steel hangers using the Romanian standards with respect with those obtained using Eurocodes.

the case study. Load tests on the pile foundation model segment, without joining its elements (pile and plate, which turns into grillage) and based on different combinations of static loadings were conducted. This proved that the loading of a plate causes skin friction on some length of the pile side surface as well as providing additional loading and settlement. Test results have shown that application of successive elements enables the foundation to carry loads up to 13% higher than in the case of a standard pile foundation loading with the same settlement

Abstract

Compared to solid or laminated timber, the main point of the design of cross-laminated timber (CLT) is very low resistance and stiffness of the CLT cross layers. For the modeling and analyzing of the load distribution in CLT, various methods are available. The aim of this paper is to present the possible ways for load-bearing analysis of structural members subjected to uniaxial and biaxial bending in various software products and using various methods. A parametric analysis was performed with the aim to compare the results obtained by the analytical method, the model of the orthotropic slab, the grillage model and using the software based on the finite element method. The values of maximum deflection obtained by selected methods were compared. The mid-span deflection of beams subjected to uniaxial bending differs only slightly. In the case of slabs subjected to biaxial bending, more visible differences in results occurred. The simplified methods give the highest values on the safe side.

References [1] Brzoska, Z., Statyka i stateczność konstrukcji prętowych i cienkościennych, PWN, Warszawa 1965. [2] Misiak, J., Stachura, S., Wybrane zagadnienia stateczności statycznej i dynamicznej konstrukcji prętowej i powłokowej , Monografia ISBN 978-83-62057-36-8, Oficyna Wydawnicza Wyższa Szkoła Ekologii i Zarządzania, Warszawa 2010. [3] Stachura, S., Static analysis and stability of the grillage , Journal of KONES Powertrain and Transport, Vol. 18, No. 1, pp. 609-614, 2011. [4] Misiak, J., Stachura, S., The influence of transverse and longitudinal

REFERENCES Dede, T., Ayvaz, Y., 2015. Combined size and shape optimization of structures with a new meta-heuristic algorithm . Applied Soft Computing, 28, 250–258. Dede, T., 2018. Jaya algorithm to solve single objective size optimization problem for steel grillage structures . Steel and Composite Structures, 26(2), 163–170. Degertekin, S.O., Lamberti, L., Ugur, I.B., 2018. Sizing, layout and topology design optimization of truss structures using the Jaya algorithm . Appl. Soft Comput. J., 70, 903–928. Grzywiński, M., Dede, T., Özdemir, Y.I., 2019

References 1. Bransby, M.F., Brown, M.J., Knappett, J.A.: Vertical capacity of grillage foundations in sand. Revue Canadienne De Géotechnique, 2011, 48(8), Pp. 1246-1265. 2. Brown, M.J., Bransby, M.F., Knappett, J.A.: The vertical capacity of grillage foundations. Géotechnique, 2012, 62(3), Pp. 201-211. 3. Chen, G.S., Liu, R.: Upper bound solutions of horizontal bearing capacity of skirted mudmat in sand. Journal of Tianjin University (Natural science and Engineering Technology Edition), 2018, 53(3), Pp. 264-270. 4. Guan, W.W., Chen, L.: International vision of

References [1] Lan T. (1999): Space Frame Structures . In Chen W.-F. & Lui E. (Eds.), Handbook of Structural Engineering (2nd ed.) – CRC Press, Boca Raton. [2] Szaniec W. and Biernacka K. (2013): Modal Analysis of Selected Bar Domes . – Structure and Environment, Kielce – vol.5, No.4, pp.15-20. [3] The European Union Regulation (2002a): Eurocode: Basis of structural design . [4] Pokusiński B. and Kamiński M. (2018): On influence of the response functions on the diagrid and orthogonal grillages reliability by the stochastic iterative perturbation-based finite

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