Features of calculating the strength of inclined sections for reinforced concrete structures under transverse and longitudinal forces according to SP 63.13330.2018

Introduction. The article discusses the SP 63.13330.2018 methodology for calculating inclined sections under the action of transverse forces, taking into account the influence of compressive longitudinal forces. The precise and simplified methods for determining average stresses, as well as the method for calculating the coefficient of the longitudinal force effect on the strength of inclined sections are analyzed. Moreover, a comparative analysis of this coefficient determined using simplified and precise methods is carried out. The shown individual shortcomings of the standard method in the area of high compressive stresses indicate the need for further research.

Aim. To consider the features of the standard methodology for calculating the strength of inclined sections for reinforced concrete elements under the action of transverse and longitudinal forces.

Materials and methods. Theoretical studies are carried out based on the results of the numerical analysis of SP 63.13330.2018 methods for calculating the strength of inclined sections.

Results. The present work includes numerical theoretical studies on a comparative analysis of calculation methods given in the standards for different reinforcement contents of concrete elements. The results demonstrate that at high stress levels and reinforcement content, standard methods may show significant discrepancies affecting the correctness of the strength assessment for inclined sections under longitudinal forces. In this regard, the need for research on this issue, including elements made of high-strength concrete, is indicated.

Conclusions. The performed analysis of standard methods for calculating the strength of inclined sections, taking into account the effect of longitudinal forces, shows that significant discrepancies in the strength of inclined sections can be observed in a number of cases with a high level of compression. The possibility of brittle failure under the action of transverse forces necessitate further research on this issue, including for high-strength concrete structures, and further development of the calculation method for inclined sections taking into account longitudinal forces.

1. SP 63.13330.2018. Concrete and reinforced concrete structures. General provisions. Updated version of SNiP 52-01-2003. Moscow: Standartinform Publ.; 2019. (In Russian).

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3. <i>Mukhamediev T.A., Zenin S.A.</i> Accounting for the Influence of Longitudinal Forces in the Calculation of Reinforced Concrete Structures on Inclined Sections. In: Modern Problems of Calculation and Design of Reinforced Concrete Structures of Multi-Story Buildings: Collection of Papers from the International Scientific Conference Dedicated to the 100th Anniversary of the Birth of P.F. Drozdova. Moscow: Moscow State University of Civil Engineering; 2013, pp. 170–174. (In Russian).

4. <i>Zenin S.A.</i> On the issue of calculations of reinforced concrete structures under the action of bending moments, longitudinal and transverse forces according to SP 63.13330.2018. Beton i Zhelezobeton = Concrete and Reinforced Concrete. 2023;616(2):50-55. (In Russian). https://doi.org/10.37538/0005-9889-2023-2(616)-50-55.

5. SP 63.13330.2012. Concrete and won concrete construction. Design requirements. Updated version of SNiP 52-01-2003. Moscow: Ministry of Construction of Russia; 2015. (In Russian).