LEFM APPLICATIONS TO CONCRETE GRAVITY DAMS

The evaluation of the safety factor of old dams under higher flood levels in the last few years has been investigated under the assumptions of fracture mechanics. The extensive need for research in this field was recognized by the U.S. Army Corps of Engineers that now requires a fracture mechanics investigation prior to the rehabilitation of cracked massive concrete structures. In large structures, such as dams, because of the smaller size of the fracture process zone with respect to the structure size, limited errors should occur under the assumptions of linear elastic fracture mechanics (LEFM). In this paper, theoretical considerations and approximate expressions for the evaluation of stress intensity factors and crack propagation in concrete dams are presented. Furthermore, a parametric study of gravity dams under the assumptions of LEFM is performed. Finally, a scale law for the evaluation of the maximum water level carried by cracked dams is proposed.

[1]  H. Rossmanith,et al.  Back face rotation correction for trapezoidal specimens , 1984 .

[2]  Victor E. Saouma,et al.  Effect of Aggregate and Specimen Size on Fracture Properties of Dam Concrete , 1991 .

[3]  Othmar-J. Rescher Importance of cracking in concrete dams , 1990 .

[4]  A. Carpinteri,et al.  Multifractal scaling law for the fracture energy variation of concrete structures , 1995 .

[5]  Anthony R. Ingraffea,et al.  Case studies of simulation of fracture in concrete dams , 1990 .

[6]  F. Erdogan,et al.  On the Crack Extension in Plates Under Plane Loading and Transverse Shear , 1963 .

[7]  Victor E. Saouma,et al.  Fracture Mechanics of Concrete Gravity Dams , 1989 .

[8]  R. S. Dunham,et al.  A contour integral computation of mixed-mode stress intensity factors , 1976, International Journal of Fracture.

[9]  Silvio Valente,et al.  Experimental and Numerical Fracture Modelling of a Gravity Dam , 1994, SP-143: New Experimental Techniques for Evaluating Concrete Material & Structural Performance.

[10]  Lennart Elfgren,et al.  Fracture mechanics of concrete structures : from theory to applications : report of the Technical Committee 90-FMA Fracture Mechanics to Concrete/Applications, RILEM (the International Union of Testing and Research Laboratories for Materials and Structures) , 1989 .

[11]  J. Rice,et al.  Elementary engineering fracture mechanics , 1974 .

[12]  Victor E. Saouma,et al.  Centrifuge Modeling and Analysis of Concrete Gravity Dams , 1995 .