STUDY OF THE INFLUENCE OF CRACKS ON THE BEARING CAPACITY OF REINFORCED CONCRETE PLATES USING THE PRINS CALCULATION COMPLEX

Objectives. In order to determine a residual safety factor, a finite element method is considered for determining the bearing capacity of reinforced concrete plates having defects in the form of cracks.

Method. The methodology is based on the use of structural calculation algorithms that take physical nonlinearity implemented in the PRINS programme into account. These algorithms assume the use of the same computational scheme in the process of solving the problem. However, the specificity of the task consists in considering differences between the calculation schemes of the initial structure and the structure having cracks.

Result. With this in mind, the algorithms of nonlinear structural analysis according to the PRINS programme are supplemented with an option that allows the parameters of the design scheme to be changed in an end-to-end calculation process. Multilayer finite elements are used to study the load-bearing capacity of reinforced concrete plates, each having a specific material package. The modernisation of the design scheme in this case consists in replacing one package of materials with another. The input file of the PRINS programme is supplemented by a description of cracks with an indication of their location and all other relevant characteristics. Examples of problems arising when determining the bearing capacity of a plate with defects in the form of cracks under various boundary conditions are given.

Conclusion. The problem of determining the bearing capacity of reinforced concrete plates with defects in the form of cracks can be effectively solved using a reconfigurable design scheme for end-to-end calculation. In the event of defects appearing in the form of cracks, this will enable operational services to monitor changes in the bearing capacity of buildings and structures containing reinforced concrete plates, as well as to determine the operability of structures and make substantiated decisions in case of repair. 

1. Kumpyak O. G.,Kokorin D. N.Fizicheskiye uravneniya zhelezobetona s treshchinami dlya dinamicheskogo rascheta konstruktsiy // Vestnik TGASU, № 4, 2015. S. 101-111. [Kumpyak O. G., Kokorin D. N. Physical equations of reinforced concrete with cracks for dynamic structural analysis // Vestnik TGASU, No. 4, 2015. pp. 101- 111. (In Russ)]

2. Kolchunov V. I., Kolchunov Vl. I., Fedorova N. V.Deformatsionnyye modeli zhelezobetona pri oso-bykh vozdeystviyakh//Promyshlennoye i grazhdanskoye stroitel'stvo.2018.№ 8.S.54-60. [Kolchunov V.I., Kolchunov Vl. I., Fedorova N.V. Deformation models of reinforced concrete under special influences // Industrial and Civil Engineering. 2018. No. 8.pp. 54-60. (In Russ)]

3. Dem'yanov A. I., Kolchunov Vl. I., Yakovenko I. A. K zadache dinamicheskogodogruzheniya armatury pri mgnovennom obrazovanii prostranstvennoy treshchiny v zhelezobetonnoy konstruktsii pri kruchenii s izgibom // Promyshlennoye i grazhdanskoye stroitel'stvo. 2017. № 9. S. 18-24. [Demyanov A. I., Kolchunov Vl. I., Yakovenko I. A. To the problem of dynamic loading of reinforcement during instant formation of a spatial crack in a reinforced concrete structure during torsion with bending // Industrial and Civil Engineering. 2017. No. 9. pp. 18-24. (In Russ)]

4. Karpenko N. I., Karpenko S. N., Petrov A. N., Palyuvina S. N. Model' deformirovaniya zhelezobetona v prirashcheniyakh i raschet balok-stenok i izgibayemykh plit s treshchinami. Petrozavodsk : Izd-vo PetrGU, 2013. 156 s. [Karpenko N. I., Karpenko S. N., Petrov A. N., Palyuvina S. N. The model of reinforced concrete deformation in increments and the calculation of beam-walls and bending plates with cracks. Petrozavodsk: Publishing House of PetrSU, 2013.156 p. (In Russ)]

5. Trekin N. N., Kodysh E. N., Trekin D. N. Raschet po obrazovaniyu normal'nykh treshchin na osnove deformatsionnoy modeli // Promyshlennoye i grazhdanskoye stroitel'stvo. 2016. № 7. S. 74-78. [Trekin N. N., Kodysh E. N., Trekin D. N. Calculation of the formation of normal cracks based on the deformation model // Industrial and Civil Engineering. 2016. No. 7. pp. 74-78. (In Russ)]

6. Dem'yanov A. I., Al'kadi S. A. Eksperimental'no-teoreticheskiye issledovaniya statiko-dinamicheskogo deformirovaniya prostranstvennoy zhelezobetonnoy ramy so slozhnonapryazhennymi rigelyami sploshnogo i sostavnogo secheniya // Promyshlennoye i grazhdanskoye stroitel'stvo. 2018. № 6. S. 68-75. [Demyanov A. I., Alkadi S. A. Experimental and theoretical studies of the static-dynamic deformation of a spatial reinforced concrete frame with complex tensioned crossbars of continuous and composite sections // Industrial and Civil Engineering. 2018. No. 6. pp. 68-75. (In Russ)]

7. Vecchio, F., and Collins, M. (1986) "The Modified Compression-Field Theory for Reinforced Concrete Elements Subjected to Shear" ACI Journal, 83(22), pp. 219–231.

8. Omar, W., (1998) “The Shear Assessment of Concrete Beams with A Honeycombed Zone Present In The High Shear Region,” Ph.D. Thesis, faculty of Engineering, University of Birmingham, 309 p.

9. Omar, W., and Clark, L.A., (2001) ‘Shear Capacity of Honeycombed Reinforced Concrete Beams’, The Structural Engineer, Journal of the Institution of Structural Engineers, UK, Vol. 79, No. 15, pp. 17-22.

10. Xie, F., (2014) “The Effect of localized low concrete strength on flexural strength of RC beams,” MS Thesis, Civil Engineering Department, Syracuse University, 336 p.

11. Abdel-Rohman, M., (2005) “Effectiveness of Patch Repair in Reinforced Concrete Beams with Exposed Honeycombs,” Kuwait Journal of Science and Engineering, Vol. 32, Issue 2, pp. 187-208.

12. Shihada, S., and Oida, Y., (2013) “Repair of Honey-Combed RC Beams Using Cementitious Materials,” International Journal of Recent Development in Engineering and Technology, Volume 1, Issue 1, pp. 1-5.

13. Al Moukdad, M.M., (2018) “Effect of Construction Void Defects on Flexural and Axial Load Capacity of Reinforced Concrete Members,” MS Thesis, Civil Engineering Department, American University of Sharjah, May, 155 p.

14. Elrakib, T.M., and Arafa, A.I., (2012) "Experimental evaluation of the common defects in the execution of reinforced concrete beams under flexural loading," HBRC Journal, Vol. 8, Issue 1, p. 47–57.

15. Agapov V.P., Aydemirov K.R. Raschet zhelezobetonnykh ferm metodom konechnykh elementov s uchetom fizicheskoy nelineynosti. Chast' 1// Nauchnoye obozreniye, 2016, № 2, s.31-34. [Agapov V.P., Aidemirov K.R. Calculation of reinforced concrete trusses using the finite element method taking into account physical nonlinearity. Part 1 // Scientific Review, 2016, No. 2, p.31-34. (In Russ)]

16. Agapov V.P., Aydemirov K.R. Raschet zhelezobetonnykh ferm metodom konechnykh elementov s uchetom fizicheskoy nelineynosti. Chast' 2// Nauchnoye obozreniye, 2016, № 3, s.22-27. [Agapov V.P., Aidemirov K.R. Calculation of reinforced concrete trusses using the finite element method taking into account physical nonlinearity. Part 2 // Scientific Review, 2016, No. 3, pp. 22-27. (In Russ)]

17. Agapov V.P., Aydemirov K.R. Issledovaniye nesushchey sposobnosti zhelezobetonnykh plit s treshchinami posle ikhusileniya kompozitnymi kanyami metodom konechnykh elementov s pomoshch'yu vychislitel'nogokompleksa PRINS// Vestnik Dagestanskogo gosudarstvennogo tekhnicheskogo universiteta. Tekhnicheskiye nauki, 2018; 45(4):142-152. DOI:10.21822/2073-6185-2018-45-4-142-152. [Agapov V.P., Aidemirov K.R. Investigation of the bearing capacity of reinforced concrete slabs with cracks after their reinforcement with composite canals by the finite element method using the PRINS computational complex // Herald of the Daghestan State Technical University. Engineering, 2018; 45 (4): 142-152. DOI: 10.21822 / 2073-6185-2018-45-4-142-152. (In Russ)]

18. Agapov V.P., Kovrigin I.I., Malakhova A.N., Savost'yanov V.N. Fizicheski nelineynyye protsessy v stroitel'nykh konstruktsiyakh. - FGBOU VPO «MGSU», Moskva, 2013. 128 s. [ Agapov V.P., Kovrigin I.I., Malakhova A.N., Savostyanov V.N. Physically nonlinear processes in building structures. - FSBEI HPE “MGSU”, Moscow, 2013.128 s. (In Russ)]

19. Prochnost', ustoychivost', kolebaniya. Spravochnik v trekh tomakh Tom 1. Izd-vo Mashinostroyeniye, M., 1968.- 831 s. [Strength, stability, fluctuations. The reference book in three volumes Volume 1. Publishing house Engineering, M., 1968 831 p. (In Russ)]