The study was carried out with the aim of obtaining load combination coefficients from the weight of different roof layers, as well as from the weight of tiling and snow load. The dependences of the obtained combination coefficients on the characteristics of the loads, as well as the feasibility of taking them into account in structural calculations, were analyzed. The selected roof structures meet the requirements of the norms for structural solutions and heat transfer resistance and cover almost the entire range of possible loads from their weight. The loads from the weight of individual layers are presented in the form of normally distributed random variables given by mean values and standard deviations. The combination coefficients are determined by probabilistic methods under the condition of equal provision of the design values of the loads from the weight of individual layers and the roof as a whole. The obtained combination coefficients vary in the range from 0.91 to 1.0. To determine them during design period, a dependence on the generalized reliability coefficient for the load from the weight of the entire roof is established. To determine the combination coefficients, statistical characteristics of the total weight of eight types of roofs and the weight of snow cover for six regions of DBN V.1.2-2:2006 were used. The method for determining the combination coefficients is based on the description of random variables of the constant load from the weight of roofs by a normal distribution and the variable snow load by the Gumbel distribution law. The obtained combination coefficients vary within 0.92…1.0. To determine them when designing truss structures, a graphical dependence on the argument is recommended, which takes into account the characteristic values of both loads, as well as the reliability coefficient for the design value of the load from the weight of the roof. Based on the results of the research, the following dependences are recommended for determining the load combination coefficients on the weight of individual layers, as well as on the roof weight and snow load. The obtained combination coefficients should be taken into account when performing verification calculations of truss structures that are in operation.

load from the roof weight, snow loads, combination coefficients

Full Text:

PDF

1. DBN V.1.2-14:2018. (2018). System for ensuring reliability and safety of building objects. General principles for ensuring the reliability and structural safety of buildings and structures. Kyiv: Ministry for Regional Development of Ukraine. [in Ukrainian]

2. DBN V.1.2-2:2006. (2020). System for ensuring reliability and safety of building objects. Loads and impacts. Design standards. With amendments No. 1 and No. 2. Kyiv: Ministry of Construction of Ukraine. [in Ukrainian]

3. DBN V.1.2-2:2006. (2007). System for ensuring reliability and safety of building objects. Loads and impacts. Design standards. Kyiv: Ministry of Construction of Ukraine. [in Ukrainian]

4. EN 1990:2002. (2002). Eurocode – Basis of structural design. Authority: The European Union per Regulation 305/2011, Directive 98/34/EC, Directive 2004/18/EC.

5. DSTU-N B V.1.2-13:2008 (EN 1990:2002, IDT). (2009). System of reliability and safety in construction. Guidance. Basics of structural design. Kyiv: Minregionbud of Ukraine. [in Ukrainian]

6. Pashynskyi, V. A. (1986). Combination of forces from atmospheric and crane loads acting on steel frames of single-story industrial buildings (Author’s abstract of PhD dissertation). Moscow. [in Russian]

7. Pashynskyi, V. A. (1999). Atmospheric loads on building structures in the territory of Ukraine. Kyiv: UkrNDIproektstalkonstruktsiya. [in Ukrainian]

8. Perelmuter, A. V., & Pichugin, S. F. (2022). On the new edition of DBN V.1.2-14:2018. Science and Construction, 32(2), 19–29. https://doi.org/10.33644/2313-6679-08-2022-2 [in Ukrainian]

9. Perelmuter, A. V., & Pichugin, S. F. (2015). Design load combinations for structural reliability assessment (review). Collected Scientific Papers of the Ukrainian Institute of Steel Structures named after V. M. Shymanovskyi, 15, 4–47. [in Ukrainian]

10. DBN 362-92. (1995). Assessment of the technical condition of steel structures of industrial buildings and structures in operation. Kyiv: Ukrarkhbudinform. [in Ukrainian]

11. DSTU B V.2.6-210:2016. (2016). Assessment of the technical condition of steel building structures in operation. Kyiv: Ministry for Regional Development of Ukraine. [in Ukrainian]

12. DBN V.2.6-220:2017. (2017). Roofing of buildings and structures. Kyiv. [in Ukrainian]

13. DBN V.2.6-31:2021. (2022). Thermal insulation and energy efficiency of buildings. Kyiv: Ministry for Communities and Territories Development of Ukraine. Retrieved from https://e- construction.gov.ua/laws_detail/3075196638495507996?doc_type=2 [in Ukrainian]

14. DSTU 9191:2022. (2023). Thermal insulation of buildings. Method for selecting thermal insulation material for building insulation. Kyiv: SE “UkrNDNC.” Retrieved from https://eurobud.ua/wp- content/uploads/2023/05/dstu-9191-2022-teploizolyacziya-budivel-metod-vyboru-teploizolyaczijnogo- materialu-dlya-uteplennya-budivel.pdf [in Ukrainian]

15. Shulhin, V. V., & Kariuk, A. M. (2013). Probabilistic representation of technical characteristics of thermal insulation materials. Collected Scientific Papers (Mechanical Engineering, Construction), 4(39)(2), 257–262. [in Ukrainian]

16. Prokopenko, D. S., & Pashynskyi, V. A. (2020). Territorial zoning of statistical characteristics of annual maxima of snow and wind loads. In Experience of introducing modern computer technologies into the educational process: Proceedings of the 2nd All-Ukrainian Student Scientific and Practical Conference (p. 37–39). Kropyvnytskyi: CNTU. [in Ukrainian]

17. Pashynskyi, V. A. (2017). Engineering method for assessing reliability indicators of steel truss rods. Bulletin of the Odesa State Academy of Civil Engineering and Architecture, 66, 48–53. [in Ukrainian].