Method of Calculation of Monolithic Reinforced Concrete Buildings in Interaction with the Base with Due Regard for Physically Nonlinear Work of Reinforced Concrete Structures

When performing numerical calculations of the system «building-base» for describing the work of building structures due to the complexity and duration of nonlinear calculation when designing, as a rule, an elastic model of the structures material is used. The account of physically nonlinear work of reinforced concrete in connection with its essential limitation when designing new structures (calculation on width of disclosure of cracks, deflections, deformations) is made simplistically by decrease in rigidity of elements with use of reducing coefficients which values are presented in norms. When calculating building deformations on the base, the stiffness of overhead structures will determine the results of the calculation of sediments and relative irregularities of sediments, the analysis of which is especially important when designing building foundations. Underestimation of physically nonlinear work of structures will lead to overestimation of rigidity of the building and accordingly underestimation of its non-uniform deformations. The article shows that when calculating the building on the deformable half-space, physically nonlinear work of reinforced concrete has a significant impact on the results of the calculation of uneven sediments of the building. A simplified method of accounting for the reduction of Flexural stiffness of the building due to the physically nonlinear operation of reinforced concrete structures is proposed, which corresponds with satisfactory accuracy to the results of joint calculations of the «building-base» system using a nonlinear deformation model of reinforced concrete. The admissibility of the proposed method is confirmed by a series of numerical calculations. The calculated deformations of the building on the base in elastic calculations, simplistically taking into account the physical nonlinearity of reinforced concrete structures operation simplified by SP 63.13330.2012 and SP 430.1325800.2018 differ significantly from the results when nonlinear calculating reinforced concrete structures.

N.A. EVSEEV, Engineer-Architect, (This email address is being protected from spambots. You need JavaScript enabled to view it.)

OOO «PI Georeconstruction» (4, Izmaylovsky Avenue, Saint-Petersburg, 190005, Russian Federation)

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