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Journal of the South African Institution of Civil Engineering

versión On-line ISSN 2309-8775
versión impresa ISSN 1021-2019

J. S. Afr. Inst. Civ. Eng. vol.50 no.1 Midrand mar. 2008

 

TECHNICAL PAPER

 

Finite element fracture modelling of concrete gravity dams

 

 

Q Cai; J M Robberts; B W J van Rensburg

 

Correspondence

 

 


ABSTRACT

A smeared crack model, based on non-linear fracture mechanics, was developed which allows for either linear or bilinear softening and assumes shear retention dependent on the strain normal to a crack. A mesh objectivity verification study proves that the proposed crack modelling method is mesh objective. The crack model and its computational procedure is verified for a benchmark concrete gravity dam model and an existing concrete gravity dam by comparing the results with those of numerical investigations obtained by other researchers. Furthermore, an existing concrete gravity dam in South Africa is analysed and evaluated with regard to dam safety in terms of the maximum overflow level. A higher imminent failure flood is predicted in the analysis than that obtained by classical strength-based methods. The study proves the usefulness and applicability of the proposed crack model and implementation procedure in predicting crack response and evaluating the safety of concrete gravity dams. A sensitivity study on the material fracture properties and fracture parameters is included for the purpose of investigating the uncertainties often encountered in this type of analysis. The influence of the fracture properties and parameters on the cracking response and the overall structural behaviour is discussed.


 

 

Full text available only in PDF format.

 

 

ACKNOWLEDGEMENTS

The Department of Water Affairs and Forestry (DWAF) is thanked for permission to publish this paper. The views expressed are those of the authors and not necessarily of the DWAF.

 

REFERENCES

Araújo, J M and Awruch, A M 1998. Cracking safety evaluation on gravity concrete dams during the construction phase. Computers & Structures, 66(1):93-104.         [ Links ]

Ayari, M L 1988. Static and dynamic fracture mechanics of concrete gravity dams. PhD thesis, Department of Civil, Environmental and Architectural Engineering, University of Colorado, USA.         [ Links ]

Barpi, F and Valente, S 2001. Time-dependent fracture of concrete dam models with fuzzy parameters. Proceedings, Fourth International Conference, edited by D M Dubois. American Institute of Physics.         [ Links ]

Bazant, Z P and Oh, B H 1983. Crack band theory for fracture in concrete. Materials and Structures, Research and Testing (RILEM, Paris), 16(93):155-177.         [ Links ]

Bazant, Z P and Pfeiffer, P A 1987. Determination of fracture energy from size effect and brittleness number. ACI Materials Journal, November-December:463-480.         [ Links ]

Bazant, Z P 1990. A critical appraisal of 'no-tension' dam design: a fracture mechanics viewpoint. Dam Engineering, 1(4):237-247.         [ Links ]

Bhattacharjee, S S and Leger, P 1993. Finite element modelling of the tensile strain softening behaviour of plain concrete structures. Engineering Computations, 10(3):205-221.         [ Links ]

Bhattacharjee, S S and Leger, P 1994. Application of NLFM models to predict cracking in concrete gravity dams. Journal of Structural Engineering (New York), 120(4):1255-1271.         [ Links ]

Bhattacharjee, S S and Leger, P 1995. Fracture response of gravity dams due to rise of reservoir elevation. Journal of Structural Engineering (New York), 121(9):1298-1305.         [ Links ]

Cai, Q, Robberts, J M and Van Rensburg, B W J 2004. Constitutive models for cracking in concrete dams -a literature review. Proceedings, Second International Conference on Structural Engineering, Mechanics and Computation (SEMC 2004), edited by A Zingoni, Cape Town: South Africa.         [ Links ]

Cai, Q, Robberts, J M and Van Rensburg, B W J 2006. Cracking in concrete using smeared cracking finite element modelling. South African Journal of Science. 102(11/12):548-556.         [ Links ]

Cai, Q 2007. Finite element modelling of cracking in concrete gravity dams. PhD thesis, Department of Civil Engineering, University of Pretoria, South Africa.         [ Links ]

Cervera, M, Oliver, J and Herrero, E 1990. A computational model for progressive cracking in large dams due to the swelling of concrete. Engineering Fracture Mechanics, 35(1-3):573-585.         [ Links ]

Chappell, J F and Ingraffea, A R 1981. A fracture mechanics investigation of the cracking of Fontana dam. Department of Structural Engineering Report 81-7, School of Civil and Environmental Engineering, Cornell University, Ithaca, New York, USA.         [ Links ]

De Borst, R and Nauta, P 1985. Non-orthogonal cracks in a smeared finite element model. Engineering Computations, 2:36-46.         [ Links ]

Ghrib, F and Tinawi, R 1995. Nonlinear behavior of concrete dams using damage mechanics. Journal of Engineering Mechanics, 121(4):513-527.         [ Links ]

Gioia, G, Bazant, Z and Pohl, B P 1992. Is no-tension dam design always safe? - a numerical study. Dam Engineering, 3(1):23-34.         [ Links ]

Horii, H and Chen, S C 2003. Computational fracture analysis of concrete gravity dams by crack-embedded elements - toward an engineering evaluation of seismic safety. Engineering Fracture Mechanics, 70:1029-1045.         [ Links ]

Ingraffea, A R 1990. Case studies of simulation of fracture in concrete dams. Engineering Fracture Mechanics, 35(1-3):553-564.         [ Links ]

Jefferson, A D 2003. Preliminary report on comparison of codes using various benchmark problems. NW-IALAD. Task Group 2.4, NW-IALAD.         [ Links ]

Jefferson, A D, Bennett, T and Hee, S C 2005. Fracture mechanics based problems for the analysis of dam concrete. Final Technical Report, Task Group 2.4, NW-IALAD.         [ Links ]

Karihaloo, B L 1995. Fracture mechanics and structural concrete. Harlow: Longman.         [ Links ]

Kumar, R and Nayak, G C 1994. Numerical modelling of tensile crack propagation in concrete dams. Journal of Structural Engineering (New York), 120(4):1053-1074.         [ Links ]

Linsbauer, H N 1990. Application of the methods of fracture mechanics for the analysis of cracking in concrete dams. Engineering Fracture Mechanics, 35(1-3):541-551.         [ Links ]

Network IALAD: Integrity Assessment of Large Concrete Dams, website (2005). Available at http://nw-ialad.uibk.ac.at/.         [ Links ]

Owen, D R J and Hinton, E 1980. Finite elements in plasticity: theory and practice. Swansea: Pineridge Press.         [ Links ]

Plizzari, G A, Waggoner, F and Saouma, V E 1995. Centrifuge modeling and analysis of concrete gravity dams. Journal of Structural Engineering, 121(10):1471-1479.         [ Links ]

Plizzari, G A 1997. LEFM applications to concrete gravity dams. Journal of Structural Engineering, 123(8):808-815.         [ Links ]

Rots, J G 1988. Computational modeling of concrete fracture. PhD thesis, Delft University of Technology, Delft, The Netherlands.         [ Links ]

Rots, J G and Blaauwendraad, J 1989. Crack model for concrete: discrete or smeared? Fixed, multidirectional or rotating? Heron, 34(1):1-59.         [ Links ]

Saouma, V E, Bruhwiler, E and Boggs, H 1990. A review of fracture mechanics applied to concrete dams. Dam Engineering, 1(1):41-57.         [ Links ]

Seddon, C V, Shelly, A J, Moore, D R and Forbes, A 1998. Report on the safety inspection of Van Ryneveld's Pass Dam. Report 2835/7938. Ninham Shand Consulting Engineers, Cape Town, South Africa.         [ Links ]

Schall, A 1988. Second geological maintenance report on Van Ryneveld's Pass Dam. Report 1988-0129. Geological Survey, Pretoria, South Africa.         [ Links ]

Shi, Z H, Suzuki, M and Nakano, M 2003. Numerical analysis of multiple discrete cracks in concrete dams using extended fictitious crack model. Journal of Structural Engineering, 129(3):324-336.         [ Links ]

Van der Spuy, D 1992. Alternative for improvement: risk-based investigation of Van Ryneveld's Pass Dam. Dam Safety Report, Report N120-01-DY03. Pretoria: Department of Water Affairs and Forestry.         [ Links ]

Van Zijl, G P A G, De Borst, R and Rots, J G 2001. The role of crack rate dependence in the long-term behaviour of cementitious materials. International Journal of Solids and Structures, 38:5063-5079.         [ Links ]

 

 

Correspondence:
Qingbo Cai
759 Lorna Street,
Moreleta Park Ext 10
Pretoria, 0044
T 012-336-8096 (w)
C 082-869-8323
DBE@dwaf.gov.za

John Robberts
Nuclear Structural Engineering (Pty) Ltd
Balblair Building
Kildrummy Office Park,
Cnr Witkoppen Road & Umhlanga Road
Paulshof, Johannesburg
T 012-319-7256
C 082-784-8743
john.robberts@nucse.com

Ben Van Rensburg
Department of Civil Engineering
University of Pretoria
Pretoria, 0002
T 012-420-2439
ben.vanrensburg@up.ac.za

 

 

 

 

JOHN ROBBERTS was associated with the Department of Civil Engineering of the University of Pretoria at the time this paper was produced. John Robberts obtained his BEng (Civil) in 1986 from the University of Pretoria and then joined this institution as lecturer in Structural Engineering. He obtained his MEng (Structural Engineering) from the University of Pretoria, and his PhD from Imperial College London. John also worked at the Atkins bridge office in Epsom (UK) and PBMR (Pretoria). John is currently a director of Nuclear Structural Engineering (Pty) Ltd. He remains involved with the University of Pretoria, as a part-time lecturer, supervising research students and presenting postgraduate courses in Reinforced and Prestressed Concrete.

 

 

QINGBO CAI was associated with the Department of Civil Engineering of the University of Pretoria at the time this paper was produced. He is a deputy chief engineer in Directorate: Options Analysis at Department of Water Affairs and Forestry. He obtained his BEng (Civil) from the Southwest Jiao-Tong University n the People's Republic of China, an MSc (Structural Engineering) from the Northern Jiao-Tong University in the People's Republic of China, and a PhD from the University of Pretoria. Over the last 20 years, he has been involved in structural design of various buildings and research on railway prestressed concrete poles and sleepers, and advanced finite element analysis of civil and mechanical structures such as dams and pipes.

 

 

BEN VAN RENSBURG is a professor in the in the Department of Civil Engineering at the University of Pretoria where he teaches and does research in structural engineering. He started his career in consulting engineering, worked in a research organization, and subsequently joined the University of Pretoria. de obtained BSc and MSc degrees in CM Engineering from the University of Pretoria, an MSc (Structural Engineering) from the University of Southampton and a PhD (Civil Engineering) from the University of Pretoria.

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