Title:
Damage and Failure of RC Flat Slabs Subjected to Impact Loading
Author(s):
David Z. Yankelevsky, Yuri S. Karinski, and Vladimir R. Feldgun
Publication:
Symposium Paper
Volume:
365
Issue:
Appears on pages(s):
79-92
Keywords:
column-slab connection, dynamic response, flat slabs, impact, progressive collapse, punching shear, reinforced concrete, shear reinforcement.
DOI:
10.14359/51746685
Date:
3/1/2025
Abstract:
Punching shear failure of RC flat slab connections cause loss of slab’s supports. The detached slab is falling and impacting the slab below. That problem requires thorough investigation and appropriate design guidelines. This paper presents research results on various aspects of this impact scenario. The analysis is based on an advanced numerical model that has been formulated, and the impact analyses follow the damage evolution in the concrete and reinforcement until complete connections failure of the impacted slab is developed, and a progressive collapse scenario starts. The effects of slab geometry and material properties were examined, and the contribution of special shear reinforcement and integrity rebars were investigated. The potential contribution of added drop panels to enhance slab resistance were examined. The slabs impact effect on the supporting columns has been investigated as well. The suitability of current static loading design-criteria to provide safe design against dynamic/impact punching shear is assessed. It shows that the current static-loading based design standards cannot ensure resilience of flat slab connections to impact loading and therefore cannot prevent a progressive collapse scenario. Analyses results are compared with inspected failure details of a collapsed RC flat slabs parking garage building, and excellent agreement is obtained.
Related References:
1. Kinnunen, S., Nylander, H., 1960, "Punching of concrete slabs without shear reinforcement", Transactions of the Royal Institute of Technology, Stockhom, Swedem Nr. 158.
2. Yamada, T., Nanni, A., Endo, K.,1992, “Punching shear resistance of flat slabs: influence of reinforcement type and ratio,” ACI Struct. J., Vol. 88 (4): 555- 563.
3. Yankelevsky, D. Z, Leibowitz, O., 1999, “Punching shear in concrete slabs,” Int. J. Mech. Sci., vol. 41, no. 1, pp. 1–15.
4. Hueste, M. B. D., Wight, J. K., 2002, “Nonlinear Punching Shear Failure Model for Interior Slab-Column Connections,” J. Struct. Eng., vol. 125, no. 9, pp. 997–1008.
5. Hallgren, M. Mats B., 2002, “Non-Linear Finite Element Analyses of Punching Shear Failure of Column Footings.” Cement and Concrete Composites 24(6): 491–96.
6. Hallgren M., Bjerke, M., 2002, “Non-linear finite element analyses of punching shear failure of column footings,” Cem. Concr. Compos., vol. 24, no. 6, pp. 491–496.
7. Muttoni, A., Ruiz, M. F., Bentz, E., Foster, S., Sigrist, V., 2013, “ Background to fib Model Code 2010 shear provisions - part II: punching shear ,” Struct. Concr., vol. 14, no. 3, pp. 204–214.
8. Einpaul, J., Ospina, Carlos, E. M., Ruiz, F., Muttoni, A., 2016. “Punching Shear Capacity of Continuous Slabs.” ACI Structural Journal 113(4): 861–72.
9. EC2, 2004, “Eurocode 2: Design of concrete structures - Part 1-1: General rules and rules for buildings,”.
10. Model code 2010, 2013, Model code 2010 : final draft. International Federation for Structural Concrete (fib).
11. ACI 318, 2014, “318-14: Building Code Requirements for Structural Concrete and Commentary,”.
12. CAN/CSA-A23.3-04 A National Standard of Canada. 2004. A23.3-04 Design of Concrete Structures.
13. Lew, H.S, Carino, N.J., Fattal, S.G., 1982, “Cause of the Condominium Collapse in Cocoa Beach, Florida.” Concrete International 4(8): 64–73.
14. Wood, J.G.M., Pipers Row Car Park, Wolverhampton: Quantitative study of the causes of the partial collapse on 20th March 1997, SS&D Contract Report to HSE, UK, 2003.
15. https://www.timesofisrael.com/dozens-injured-20-trapped-as-building-collapses-in-tel-aviv/
16. Mirzaei, Y., 2010, Post-Punching Behavior of Reinforced Concrete Slabs, Ph.D. Thesis, Ecole Polytechnic Federale Lausanne, Switzerland
17. Ruiz, M.F., Mirzaei, Y., Muttoni, A., 2013, “Post-Punching Behavior of Flat Slabs.” ACI Structural Journal 110(5): 801–12.
18. Ulaeto, N. W., Sagaseta J., 2022, “A post-punching shear model for column–slab connections for progressive collapse analyses”, Magazine of Concrete Research, 74 (6) pp. 284-302.
19. Yankelevsky, D. Z., Karinski, Y. S., Feldgun V. R., 2020, “Dynamic punching shear failure of a RC flat slab-column connection under a collapsing slab im,pact,” Int. J. Impact Eng., vol. 135 (2020) 103401.
20. Yankelevsky, D. Z., Karinski, Y. S., Brodsky, A., Feldgun, V. R., 2021, “Evaluation of punching shear design criteria to prevent progressive collapse of RC flat slabs,” Int. J. Prot. Struct., vol. 12 (2): 174–205.
21. Yankelevsky, D.Z., Karinski, Y.S., Brodsky, A., Feldgun, V.R., 2021, "Dynamic punching shear of Impacting RC flat slabs with drop panels", Engineering Failure analysis, Vol. 129, No. 2021, doi: 10.1016/j.engfailanal.2021.105682
22. Yankelevsky, D.Z. *, Karinski, Y.S., Tsemakh, D., Feldgun, V.R., From impact of RC flat slabs in a building to its progressive collapse, Int. Jour of Protective Structures, Special issue, Vol 13(2) 439-466, 2022
23. Yankelevsky, D.Z., Karinski, Y.S., Feldgun, V.R., Damage evolution in the event of impact punching shear of RC flat slabs, ASCE-Jour of Performance of constructed facilities, 2023, 37(4): 04023024
24. Yankelevsky, D.Z., Karinski, Y.S., Feldgun, 2024, V.R., Tsemakh, D., Column core response during progressive collapse of RC flat slabs, Engineering Failure Analysis, 158 (2024) 108028
25. ANSYS AUTODYN, 2005, Theory manual. revision 4.3.
26. Herrmann W. Constitutive Equation for the Dynamic Compaction of Ductile Porous Materials, J. Appl. Phys., 40(6), 1969: 2490-2499.
27. Riedel, W., Wicklein, M., Thoma, K. 2008 “Shock properties of conventional and high strength concrete: Experimental and meso-mechanical analysis.” Int. J. .Impact Eng. 35(3): 155–171.
28. Riedel W, Kawai N, Kondo K-I., 2009, “Numerical assessment for impact strength measurements in concretematerials”. 2009 Int J Impact Eng 36(2):283–93.