The need for reliable supports for locating and maintaining the equipment of cellular opera-tors is increasing every year. The classic version of the supports are lattice towers. At present, optimization of the parameters of lattice towers, which is one of the ways to improve the efficiency of their design and construction, is of great importance. The purpose of the work is chosen definition of a rational constructive form of lattice cellular communication towers. In the work, the calculation and analysis of the tower supports of a prismatic and pyramidal form are made with varying basic geometric parameters of the structure and the ratio of parameters between them. To create basic dependencies, numerical modeling methods are used. According to the results of a critical analysis of the literature on the calculation of lattice supports of high-rise buildings, the absence of recommended optimal values of the geometric parameters of structures and the relationship between them was established. The stress-strain state of the design models of lattice towers of a prismatic and pyramidal shape was assessed with variation of the main overall geometric parameters of the structures. To achieve the goal of finding a rational structural form of lattice supports, two rationalization criteria have been tested and applied - the simultaneous fulfillment of the requirements of both limiting states and minimization of the mass of the structure. The results of the study of lattice tower supports are presented in dimensionless parameters, which can be applied by the engineer when assigning the overall dimensions of the structure at the initial design stage.

In some cases, architectural, technological or other special requirements dictate the development of buildings and structures with large spans of shells. The choice of the scheme of bearing structures depends on the size of the span, architectural and planning solutions, the shape of the building in plan, the height of the structure, the presence and type of suspended transport, the requirements for the rigidity of the shell, the nature of lighting and aeration, type of roof, size and distribution of loads, the need to accommodate large masses of people and other factors. Differences in the purpose of large-span buildings and structures, features of technological processes, architectural and aesthetic requirements determine the use of a variety of solutions of such coatings.The article presents design measures for the implementation of architectural and artistic solutions of the building of the Dolphinarium in Volgograd. Analytical description of complex architectural and structural forms is performed. The analysis of existing structural forms of large-span structures is given. In the design, the concept of a combined archcable system was implemented, in which the cable system acts as an unloading and supporting system. The study of the work under load of various schemes of the cable system. It was also investigated the influence of pre-tensioning braces on strain supported their designs, and from what was determined optimal value of the efforts of the cables tension.

Волгоградский государственный технический университет, Российская Федерация, 400131, Волгоград, просп. Ленина, 28 Ключевые слова: проектирование; металлические конструкции; стальная башня; новое конструктивное решение; параллельные затяжки; расчетная схема; конструирование; сравнительный расчет Аннотация Актуальность. Одним из основных направлений развития систем мобильной связи, радиотехнических и телекоммуникационных систем является совершенствование конструктивной формы несущих опор, что позволит решить ряд практических задач: увеличить зону покрытия, обеспечить более высокие показатели скорости передачи данных и стабильность работы в условиях растущего количества пользователей. Указанные обстоятельства обосновывают актуальность исследований в данном направлении.Цели. Задача исследования заключалась в оптимизации конструктивного решения башен с параллельными затяжками, обеспечивающего возможность возведения и безопасной эксплуатации на протяжении заданного срока службы путем выполнения требований по прочности, устойчивости и деформациям к таким сооружениям при минимальной материалоемкости.Методы. Для расчетов применялся метод конечных элементов для математического моделирования с использованием программно-вычислительных комплексов, а при создании линейки моделей для численных экспериментов -метод математического планирования экспериментов.Результаты. В статье рассмотрена работа башен предложенного конструктивного решения в качестве опор для размещения оборудования операторов сотовой связи на примере башни высотой 42 м. Для установления основных характеристик напряженно-деформированного состояния конструкций опор созданы и рассчитаны модели в программных комплексах, в основу работы которых заложен метод конечных элементов. Выполнен сравнительный анализ усилий в оттяжках, определенных аналитическим расчетом и методом конечных элементов, а также анализ изменения напряженно-деформированного состояния башен от воздействия влияющих факторов, таких как ветровая и гололедноветровая нагрузки, угол наклона оттяжек на нижнем ярусе башни. По критерию минимальной металлоемкости и технологичности возведения башен определены рациональные габаритные размеры башни. Предложены варианты конструирования основных узлов сопряжений элементов башни.

Relevance. Beam cages are the most common type of floor covering for working areas of buildings and structures. Based on the results of a critical analysis of the existing methods for calculating and arranging the dimensions of beam cells, it was established that there are no clear recommendations on the rational range of selection of the sizes of beam cells depending on the surface load. The purpose of the study is to present the areas of rational operation of steel rolling beams, secured against buckling, based on the requirements of the calculation by the method of limit states. Methods. The tasks set in the work, aimed at achieving the research goal, are solved by analytical methods, relying on the basic laws of structural mechanics and existing knowledge about the actual operation of steel rolling beams under load. Methods of mathematical statistics were used to construct the main dependencies presented on the nomograms. Results. Areas of rational operation of steel rolling beams, secured against curvatures, are determined. The area of rational operation of beams is presented in the form of nomograms, which allow at the design stage to use a beam cell of maximum dimensions. As a criterion for rationalization, the criterion of the simultaneous satisfaction of the accepted section of the beam with the requirements of two groups of limiting states with minimum reserves was chosen. A refined algorithm for the layout of the beam cages and a refined method for calculating the cross-section of rolled beams are proposed, which make it possible to arrange the dimensions of the beam cage with a minimum steel consumption. The increase in the overall dimensions of the cells of the working platforms is substantiated.

Relevance. Due to the widespread use in practice, tubular furnaces were chosen as the object of study of this work. The article provides an analysis of damage to the supporting structures of oil refining tubular furnaces. The causes of damage and the physical nature of the development of damage are established. According to the results of field surveys, it was found that about 10% of the furnaces are operated with damage in the form of significant curvature of the supporting structures that developed as a result of the explosion of the gas-air mixture and the technological product inside the furnace space. The aim of the work is to analyze the damage and assess the impact of damage on the operation of the supporting structures of furnaces. Methods. The main research results were obtained by static numerical analysis of spatial models of furnace frameworks in the LIRA-SAPR software package. This complex belongs to the class of software products that implement the finite element method. Results. According to the results of calculating a series of models of structures, the effect of damage on the operation of the supporting structures of the furnace is determined. Based on the analysis of calculation data for models of tube furnaces with damage and comparison of calculation results for furnace models with structural damage identified during the survey, ways to optimize the design decisions of an industrial furnace are determined. Studies have shown the need to improve the design of tube furnaces in the direction of improving technology and improving the structural form of the supporting frame of the furnace.