Probe of Crack Initiate at the Toe of Concrete Gravity Dam using Numerical Analysis

Authors: M. S. Salimi, H. Kiamanesh, N. Hedayat

Abstract:

In this survey the process of crack propagation at the toe of concrete gravity dam is investigated by applying principals and criteria of linear elastic fracture mechanic. Simulating process of earthquake conditions for three models of dam with different geometrical condition, in empty reservoir under plain stress is calculated through special fracture mechanic software FRANNC2D [1] for determining fracture mechanic criteria. The outcomes showed that in spite of the primary expectations, the simultaneous existence of fillet in both toe and heel area (model 3), the rate of maximum principal stress has not been decreased; however, even the maximum principal stress has increased, so it caused stress intensity factors increase which is undesirable. On the other hand, the dam with heel fillet has shown the best attitude and it is because of items like decreasing the rates of maximum and minimum principal stresses and also is related to decreasing the rates of stress intensity factors for 1st & 2nd modes of the model.

Keywords: Stress intensity factor, concrete gravity dam, numerical analysis, geometry of toe.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1332504

References:

[1] G. Cornell Fracture Group, "FRANC2D: A Two Dimensional Crack Propagation Simulator Tutorial and User's Guide", Version 3.1, 2003.
[URL: http://www.cfg.Cornell.edu/]
[2] Soauma V.E. & Milner D.," on why Fracture Mechanics should be Adopted for Dam Safety Investigation", Dam Engineering, VD VII, Issue3, PP 215-229, 1996
[3] Galves J. & Lorca J.L. & Elicess. M, "Fracture Mechanics Analysis of Crack Stability in Concrete Gravity Dams", Dam Engineering, vol. VII, Issue1, PP 35-63, 1996
[4] Plizzari G.A., "LEFM Application to Concrete Gravity Dam", Journal of Engineering Mechanics, vol.123, No.8, PP 808-815, 1998
[5] Bazant Z.P., "Instability Ductility and Size Effect in Strain - softening Concrete", Journal of Engineering Mechanics Division, ASCE, vol.102, No.EM2, 1976, PP.331-344
[6] Bazant Z.P., "Fracture in Concrete and Reinforced Concrete", In: Bazant Z.P. editor, IUTAM Symposium on Mechanics of Geo-Materials, Northwestern University,1983, PP.281-316
[7] Bazant Z.P. & oh B.H., "Crack Band Theory for Fracture of Concrete", Materials and structures, RILEM, vol.16, 1983, PP.155-177
[8] Rahimian M. & Amini A., " Three Dimensional Crack Growth Analysis in Litian Buttress Concrete Dam by using smeared crack " Tehran University reviews , Vol.37, 2004,pp235-243
[9] Atar nejad R. & Lohrasbi A., "Crack Growth Analysis in Concrete Gravity Dams by Using Discrete Crack "1st National Congress on Civil Engineering, 2004.
[10] Madandost R. & Lashte neshaei M. & Hatami F., " Analyze the Effect of Reservoir Water Level in Determining Earthquake Forces in Concrete Dams "2nd International Conference on Concrete and Development, 2005.
[11] Vothuqi far H. Adl parvar M. R. shamsaei A., " Seismic Analysis Concrete Gravity Dams Having Crack by applying mixed method finite volume- finite element "2nd International Conference on Concrete and Development, 2005.