Girders of Hydraulic Gates Optimal Design

Abstract. When building a new block of a health and recreation center, designer metal structures were used in the roofing coverage. The over covered three storey building consists of two blocks. It has a variable height and a mixed framework. Both building blocks were over covered with structural lattice roofing of similar design. When designing spatial structural roofing, the authors proposed a new design concept. The novelty of the design lies in the fact that a modified flat truss is used as the basic assembly unit of a spatial structure. To develop a spatial structure design the roof-girder trusses with continuous chords from rolled I-beams and a lattice from roll-welded sections with non gusset joists were used. They are well-known and work well in practice. When designing structural roofing, previously known trusses of the mentioned design were slightly modified. In particular, trusses with parallel chords were given greater camber (2.5% instead of 1.5%), the design of a supporting truss joist was changed and fixing elements for chord and lattice members joining trusses into a spatial structure were added to truss joists.

Section: Main Partmentioning

confidence: 99%

Metal structural roofing with a flat truss with continuous chords as an enlarged assembly unit

Alpatov

2016

“…The process is also facilitated by numerous studies of thin-walled profiles, the ways they accommodate different types of loads [7][8][9][10][11][12][13][14][15] and research of their joint connections [9,[11][12][13][14][15][16][17][18][19][20][21][22][23][24]. The best results in designing of LSTS can be achieved by applying methods of optimal design of structures [25][26][27]. Analysis of accumulated statistics on accidents and building collapses with the use of LSTS makes it possible to point out one of the most frequently encountered errors -a mistake in the design and construction of nodes.…”

Section: Introductionmentioning

confidence: 99%

Thin-walled profiles and their joint assembly units built with screws: numerical studies of load bearing capacity

Alpatov

Soloviev

2018

There is a tendency to reduce weight of load-bearing metal structures being developed and successfully realized in modern building construction. This idea serves as a basis for a whole scientific direction, named Development and application of light steel thin-walled structures (LSTS). Among them, LTST built with pop-rivets and thread-cutting screws are most widespread due to their simplicity and relative cheapness This paper presents numerical studies of LSTS joint assembly units built with screws and their load bearing capacity. The peculiarity of these units consists in misalignment of joint elements. The calculation was performed in the SolidWorks Simulation System. The modeled node is a threedimensional assembly consisting of solid components. The results of the study are as follows: 1) thin-walled profiles have a significant sensitivity to eccentricity; 2) it is unacceptable to disregard eccentricities for thin-walled profiles and their joint connections; 3) eccentricities should be compensated by measures to improve reliability in joint connections design.

“…Most concrete structures operate under conditions of intensive environmental impact [1][2][3][4][5]. Effects on concrete structures can be mechanical, chemical, thermal, radiation, etc.Temperature variation during the year can vary widely over 1000 C, and humidity-from 0% to 100%.…”

Section: Introductionmentioning

confidence: 99%

Complex characteristic for forecasting durability of hydraulic concrete

Popov

Davidenko

2018

The paper analyzes operating conditions of hydraulic structures, as well as the main types of external influence with temperature and humidity variations. The purpose of the research is to highlight the main parameters which will be able to assess the actual durability of concrete hydraulic structures in the process of their design. The authors use methods developed in Samara Architecture and Civil Engineering Institute to determine concrete physical and mechanical characteristics. Thus, these methods help accurately assess concrete durability, frost resistance and water resistance. These methods are based on theoretical studies of the processes of concrete destruction by means of non-destructive acoustic methods. The the energy conception developed by A.A. Griffits and S.N. Zhurkova's kinetic serve as a scientific basis for the methods. Theoretical research and its analysis of concrete destruction processes from various kinds of external influence was confirmed by results of standard measurements. The research showed that durability of concrete, that is speed of its destruction, depended on two groups of physical and mechanical characteristics. One of the groups evaluates the initial structure of concrete, while the second group characterizes the speed of the material loading . The paper proposes a forecasting method of frost resistance and water-resisting properties of concrete according to its physical-mechanical characteristics. It also introduces an indicator of their assessment which is named the length of the reduced crack. The proposed indicator has a good correlation with frost resistance and water-resisting properties . Besides, the proposed method can be used not only in laboratory conditions, but also in construction production directly on the construction site.