LIRA-SAPR: experimental and theoretical verification of calculations

Introduction. This article continues the discussion. The LIRA-SAPR software package, widely used in Russia, is examined. Due to its many positive qualities, it is used by various design, educational, and regulatory organizations. However, the results of calculations for reinforced concrete structures raise the doubts and questions discussed in this article. Numerous requests to the developers for clarification, unfortunately, remain unanswered.

Aim. To verify the accuracy of the LIRA-SAPR software’s calculations for reinforced concrete structures.

Materials and Methods. Three test cases were considered: an experimentally verified floor slab, a foundation slab, and a slab from the LIRA-SAPR Software User’s Guide. The reinforcement of the structures was determined using LIRA-SAPR and compared with experimental data, as well as with the results obtained using the OM SNiP Zhelezobeton software using a nonlinear deformation model and the ultimate force method.

Results. The results of the LIRA-SAPR reinforcement calculations were, in our opinion, incorrect: the reinforcement consumption in these cases exceeded the standard requirement by several times – 3.8, 9, and 3.1.

Conclusions. Due to the significant, unjustified excess consumption of reinforcement, as demonstrated by the examples provided, the LIRA-SAPR program in its current form can only be used to determine forces, but not to calculate the reinforcement of reinforced concrete structures. We believe it is necessary to discuss this situation with the program’s developers and take measures to rectify it. The authors believe one possible solution is to use LIRA-SAPR only to determine forces, and to calculate the reinforcement for these forces using the OM SNiP Zhelobeton program, which takes into account all regulatory requirements. At the same time, it is necessary to note the need for further improvement of the standards. 

1. Krakovsky M.B., Tikhonov I.N. On methods of calculation of reinforced concrete structures. Concrete and Reinforced Concrete, 2026, vol., no. 1(632), pp. 20–28. (In Russ.) https://doi.org/10.37538/0005–9889–2026–1(632)-20–28.

2. SP 63.13330.2018. Concrete and Reinforced Concrete Structures. Basic Provisions. Updated version of SNiP 52–01–2003. Moscow, 2018.

3. Tikhonov I.N., Levi M.I., Sokolov V.P., Nikolsky V.A., Chebykin B.A., Ponomarev S.A. Use of At-IYC steel in the production of floor slabs for residential buildings. Concrete and Reinforced Concrete, 1990, no. 11. pp. 4–5.

4. Reinforced concrete frame in Lira Sapr. Lesson 14. Selection of reinforcement. Foundation slab. URL: https://yandex.ru/video/preview/7750813489611099530

5. Romashina M.A., Titok V.P. LIRA-SAPR Software Package. User’s Guide. Tutorials. 2018. 254 pages. URL: https://rflira.ru/files/lira-sapr/Book_LIRA_SAPR_2018.pdf?ysclid=mo7ar1j2sa901946363