пешеходные мосты в Нижнем Новгороде. Представлены качества алюминиевых сплавов, выгодно отличающие их от других строительных материалов. Авторы рассмотрели технологию замены сталежелезобетонных плит проезжей части мостов на алюминиевую плиту, что позволяет в несколько раз снизить вес конструкции при значительном увеличении грузоподъемности реконструируемого моста. Помимо ряда очевидных преимуществ мостов из алюминиевых сплавов, указаны факторы, сдерживающие их более широкое внедрение на территории Российской Федерации. Перечислены нормативные документы, действующие в США и странах Европейского Союза. Рассмотрена программа испытаний серии образцов из нескольких алюминиевых сплавов и полноразмерного пешеходного моста с целью определения характеристик этих материалов. Применение алюминиевых сплавов в строительстве мостов является выгодным с коммерческой точки зрения, снизит влияние операций технического обслуживания конструкций на окружающую среду, приведет к минимизации потребления материалов.

Introduction. The article deals with getting an orthotropic deck plate, made of aluminum alloy EN-AW-6082 T6, involved in the structural performance of bearing structures of bridges; this type of plates is made by extruding composite plate elements, or hollow rods having closed rigid profiles of the pre-set shape, friction welding and mixing. These technologies are applied to make an orthotropic plate, a strong rigid metal structure that can be effectively integrated into the structural performance of bearing structures of a bridge superstructure to reduce the consumption of materials. Materials and methods. The object of the study is a conventional single-span road bridge, which is 8.06 m long. The bridge has two bearing I-beams, five transverse I-beams and a deck made of four orthotropic plates placed perpendicular to the bridge axis. The numerical simulation of this structure was conducted to determine the numerical parameters of a change in the consumption of materials for various applications of orthotropic plates in bridge deck structures. The ANSYS software package was employed to simulate the following three models: a model in which orthotropic plates were not involved in the structural performance; a model that had orthotropic plates involved in the structural performance, and a model that had optimized geometric dimensions of sections of principal bearing beams and plates involved in the structural performance. Results. The calculation results are provided in the form of diagrams of stresses and deflections along the bearing beams, the diagram of stresses in the cross-sections of bearing beams in the middle of the bridge span. Compared results of various calculation patterns are also provided. The amount of metal saved goes down with an 8–24 m increase in the span length, and it reaches 25–7 %, respectively. Conclusions. The authors present their research findings, evaluate the effectiveness of this approach applied to the design of bridge structures, and make a conclusion about the spans of structures that make this approach most effective.

Introduction. The article is focused on evaluating the stress-strain state of nonreinforced arch cover structures made of thin-walled cold-formed profiles and arch cover structures reinforced by arch frames made of triangular trusses and girders. The relevance of the study is backed by the need to reinforce arch covers in the event that the design area of operation of a structure is different from the actual area of operation, which is confirmed by the recent cases of collapse of these structures. To reduce the labour input into simulation, the authors suggest a 3D modelling methodology presented using the case of a hangar reinforced by orthotropic plates and rods. Materials and methods. A 2D analysis of an arch was performed using the parameters of the reduced cross-section and a 3D analysis of the same arch was performed using a combined cross-section of plates and rods to verify the methodology. The 2D arch and 3D models were subjected to snow loading in compliance with the regulatory document document SP 20.13330.2016 “Loads and impacts”. Parameters of reduced straight sections and stresses, arising in the 2D arch, were analyzed on the basis of identified internal forces and the regulatory document SP 260.1325800.2016 “Thin-walled steel structures made of cold-formed galvanized profiles and corrugated sheets”. A reduction in the rigidity of corrugated sections is taken into account by assessing the rigidity subjected to the effect of a single force. Finite element modeling was conducted in SCAD Office software; stresses and displacements were calculated automatically. Results. The 3D calculation method involving orthotropic plates and rods showed satisfactory convergence with the calculation made in the two-dimensional formulation. Maximum stresses arising in a 3D model are 2 % lower than in a 2D arch, and maximum displacements are 21 % lower thanks to a more accurate FEM analysis of the 3D behaviour of the whole hangar. Conclusions. The proposed modeling technique reduces the labor intensity of structural modeling and is suitable for evaluating the joint behaviour of basic and reinforced structures of any type.