A fracture mechanics based seismic analysis of concrete gravity dams using discrete cracks

The phenomenon of interface crack propagation in concrete gravity dams underseismic loading is herein addressed. This problem is particularly important from the engineeringpoint of view. In fact, besides Mixed-Mode crack growth in concrete, dam failure is oftenthe result of crack propagation along the rock-concrete interface at the dam foundation. Toanalyze such a problem, the generalized interface constitutive law recently proposed by the¯rst author is used to proper modelling the phenomenon of crack closing and reopening at theinterface. A damage variable is also introduced in the cohesive zone formulation in order topredict crack propagation under repeated loadings. Special attention is given to the complexityresulting from the solution of the nonlinear dynamic problem and to the choice of the interfaceconstitutive parameters, taking into account the important size-scale e®ects observed in thesecyclopic structures. Numerical examples will show the capabilities of the proposed approachwhen applied to concrete gravity dams.

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Three-Degree-of-Freedom Rigid Model for Seismic Analysis of Cracked Concrete Gravity Dams

Journal of Engineering Mechanics ◽

10.1061/(asce)0733-9399(2006)132:9(979) ◽

2006 ◽

Vol 132 (9) ◽

pp. 979-989 ◽

Cited By ~ 10

Author(s):

O. A. Pekau ◽

Xueye Zhu

Keyword(s):

Seismic Analysis ◽

Degree Of Freedom ◽

Gravity Dams ◽

Cracked Concrete ◽

Concrete Gravity Dams ◽

Rigid Model ◽

Three Degree Of Freedom

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Damage estimation on concrete gravity dams through artificial accelerograms

MATEC Web of Conferences ◽

10.1051/matecconf/201821114001 ◽

2018 ◽

Vol 211 ◽

pp. 14001

Author(s):

Enrico Zacchei ◽

José Luis Molina

Keyword(s):

Response Curve ◽

Seismic Analysis ◽

Response Spectrum ◽

Damage Index ◽

Spectral Density Function ◽

Gravity Dams ◽

Concrete Gravity Dams ◽

Power Spectral ◽

The Time Domain ◽

Artificial Accelerograms

The aim of this paper is to analyse the damage on gravity dams through artificial earthquakes from two methods. The first procedure defines the performance and the response curve of concrete gravity dams using a harmonic function which establishes linear displacements. The other procedure to obtain the artificial earthquake defines the power spectral density function consistent with the response spectrum. This artificial accelerogram is necessary to quantify the response curve of concrete gravity dams in the time domain. The seismic activity in Spain is not frequent, therefore it is often difficult to select real accelerograms to perform a complete seismic analysis, which makes artificial accelerograms extremely useful. Finally, combining these two procedures, a damage index is determined for assessing the crack’s magnitude. These both efficient and practical procedures are useful to develop further complicated analysis.

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Concrete constitutive models for nonlinear seismic analysis of gravity dams — state-of-the-art

Canadian Journal of Civil Engineering ◽

10.1139/l92-059 ◽

1992 ◽

Vol 19 (3) ◽

pp. 492-509 ◽

Cited By ~ 16

Author(s):

Sudip S. Bhattacharjee ◽

Pierre Léger

Keyword(s):

Finite Element ◽

Fracture Mechanics ◽

Crack Propagation ◽

Seismic Analysis ◽

Numerical Models ◽

Ground Motions ◽

Constitutive Models ◽

Concrete Dams ◽

Gravity Dams ◽

Seismic Safety

The seismic safety of concrete dams is a matter of serious concern around the world. During severe ground motions, the dams are likely to experience cracking due to low tensile resistance of concrete. Several analytical methods have been proposed in the literature for finite element crack propagation analysis of concrete structures. Due to lack of consistent results, and virtually impossible verification because of limited field experience in seismic cracking of concrete dams, the choice of a reliable constitutive model has become a complex task. A review of concrete constitutive models for nonlinear seismic analysis of gravity dams is presented herein. The relative merits of the proposed models have been critically examined. Comparing the theoretical soundness, and the advantages and inconveniences of the different analytical procedures, the nonlinear fracture mechanics model applied with a smeared crack analysis technique appears to be very promising. The present state of knowledge on material fracture parameters under transient conditions has been found to be limited. Review of the past finite element seismic fracture analyses of concrete gravity dams reveals that reliable numerical models for safety evaluation of the structures during severe ground motions have not yet been satisfactorily developed. Key words: gravity dams, constitutive models, fracture mechanics, seismic response, nonlinear analysis, finite element, crack propagation.

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