Structural Mechanics of Engineering Constructions and BuildingsStructural Mechanics of Engineering Constructions and Buildings1815-52352587-8700Peoples’ Friendship University of Russia (RUDN University)2359310.22363/1815-5235-2020-16-2-87-94Research ArticleProbabilistic estimation seismic resistance of spatial steel frame under earthquakeMkrtychevOleg V.<p>Doctor of Technical Sciences, Professor of the Strength of Materials Department</p>sergey.bulushev@gmail.comBulushevSergey V.<p>engineer of the research center “Reliability and Seismic Stability of Structures”</p>sergey.bulushev@gmail.comMoscow State University of Civil Engineering (National Research University)15122020162879429042020Copyright © 2020, Mkrtychev O.V., Bulushev S.V.2020<p>Relevance. By its nature, seismic action is represented by the accelerogram a pronounced multidimensional random process, generally containing six components. The calculation in the deterministic formulation does not always allow to adequately assess the reaction of the system. While the calculation in the probabilistic formulation more adequately reflects the work of the system and makes it possible to evaluate its seismic resistance with a given security. The aim of the work is to assess the actual load-carrying capacity safety margin and the taken when designing coefficient K1, taking into account the permissible damage to buildings and structures for the steel spatial frame when calculating on the seismic action. Methods. In the article, the steel spatial frame was calculated for two sets of accelerograms, with dominant frequencies close to the main frequencies of the frame's natural vibrations. Each set was synthesized as a family of unsteady random seismic impact implementations. The calculation was carried out on two-component seismic action in nonlinear dynamic formulation in the software complex LS-DYNA. Previously, the frame was designed in accordance with national standard SP 14.13330.2014 Construction in seismic areas on the seismic action of the design earthquake level in the software complex PC LIRA 10.8. According to the developed probabilistic method for each set the actual load-carrying capacity safety margins were obtained and the coefficients K1 were estimated. Results . An analysis of the results shows that the steel frame under consideration has a sufficiently large margin of load-carrying capacity, and the coefficient K1 is taken in norms excessively conservatively. The developed technique allows to correct the value of the accepted coefficient K1 for buildings and structures of certain structural schemes. That in its turn will increase the economic efficiency of construction in seismic areas and ensure the reliability of the designed buildings and structures.</p>LS-DYNAseismic stabilitynonlinear dynamic calculation methodaccelerogramrandom processexplicit integration methodLS-DYNAPC LIRAtheory of reliability of construction structuresprobabilistic methodsmethod of statistical testsсейсмостойкостьнелинейный динамический метод расчетаакселерограммаслучайный процессявный метод интегрированияПК ЛИРАтеория надежности строительных конструкцийвероятностные методыметод статистических испытаний[Mkrtychev O.V., Bulushev S.V. Actual problems of earthquake engineering. “Loleyt readings – 150”. Modern methods of calculation of reinforced concrete and stone structures by limit states (Moscow, November 30, 2018). 2018: 270–278. (In Russ.)][Mkrtychev O.V., Dzhinchvelashvili G.A. Assessment of buildings and structures beyond the elastic limit at the seismic influences. 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