Calculation and Design of the Wooden Lens-Shaped Truss with the Value of Snow Load on the Horizontal Ground Surface 3.2 Kpa

Author Name(s): Sabina M. Rzaeva, Svetlana V. Zonina, Lida A. Feoknistova, Tatiana V. Rzaeva
Author Email: tania14.11@mail.ru

Abstract

In this paper, they considered the algorithm for a lenticular shaped truss calculation, in accordance with the set of rules “Wooden glued and all-wood structures” SNiP II – 25 – 80 (CR 64.13330 – 2011).

The results of load calculation concerning the own weight of the truss, the calculation of the uniformly distributed constant load located on the whole span, the calculation of the distributed snow load with the triangular outline are presented. The calculated forces in the elements of the truss are determined by the methods of knot cutting out, the longitudinal forces N and the bending moments M are calculated in the upper belt panels. The section of the truss is selected and checked. The result of the above calculations is a positive evaluation of a building design possibility with the span of 24 m at the calculation of the load-bearing structures for the maximum possible loads, where a wooden segmented lens-shaped truss is proposed as a cover.

Introduction

Every year in our country and throughout the world [1] the production of glued timber increases. The structures of glued wood are used for the frameworks of buildings and structures of various functional purposes. Accordingly, the range of load-bearing wooden structures is constantly expanding by the improvement of known and the development of fundamentally new constructive solutions. The types of the structures without bars are of interest along with arched covers and frames. One of the most effective ones, especially for large spans, is the truss with curved belts, the so-called lens-shaped one [2,8].

If we compare lens-shaped trusses with other types, the lens-shaped have a number of features and advantages, for example, they differ by a relative simplicity of manufacturing and assembly, which reduces labor intensity and shortens the production time, which in its turn is economically profitable.

In recent years, dozens of different buildings and structures have been built in Russia using lens-shaped beams with large spans. These space-planning solutions differ favorably by the functionality of architectural forms.

In this paper, one of the reasons to choose a glued wood lenticular truss is the projected building of the exhibition center with a large span of 24 m. The interest is presented both from the scientific and practical point of view and from the architectural and aesthetic aspect, but it is necessary to test for strength under given climatic loads for the realization of this project.

The main features of lens shaped and design trusses efficiency calculation are reflected in the new updated version of SNiP II – 25 – 80 (CR 64.13330 – 2011) [3].

Conclusions

According to the results of the performed work, it can be concluded that the selected design, namely the wooden segmented lens farm, can be chosen as a cover for a building with the span of 24 m, in the construction area – V snow (Naberezhnye Chelny) with the estimated value of the snow load on the horizontal the ground surface of 3.2 kPa.

And although the obtained results do not exceed the normative values ​​of the design load, the additional reinforcement of the support area of ​​the truss support units should be considered possible during the design of buildings and structures with large spans or in the cases of snow loading exceeding the normalized values ​​for the V snow area of ​​construction [4]. In this work, the technical and economic indicators for the consumption of materials were not considered due to the distribution of the belt material over the span, and this once again favorably distinguishes lens-shaped trusses from the traditional building structures of the coating [5].

And also issues about the durability of wooden constructions and the protection from ignition remained uncovered. But with existing standards, the lifetime of wooden structures increases [6,7].

Acknowledgements

The work is performed according to the Russian Government Program of Competitive Growth of Kazan Federal University.

References

  1. Richmond Olympic Oval [Electronic resource] // Naturally: wood. – Access terms: naturallywood.com/sites/default/files/Richmond-Olympic-Oval-Case-Study.pdf
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  8. Turkovsky S.B. Rational applications of load-bearing glued wooden structures (GWS) “TsNIISK Systems” / S.B. Turkovsky, A.A. Pogorel’tsev // The collection of scientific works “Modern building constructions of metal and wood” – OGASA. – Issue № 15. – Part 2. – Odessa, 2011. – pp. 217-225.
  9. Code of regulations CR 20.13330.2011 “Loads and effects.” (updated version of SNiP 2.01.07-85*) – M.: OJSC “TsPP” 2011.

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