Cracking Development Prediction in Concrete Gravity Dams Using Concrete Damage Plasticity Model
Abstract
As it is well known, many dams around the world are placed in seismic zones. Because of this, it should be check if they can resist dynamic loads typically associated with earthquake occurrences. According to USACE manual (ER 1110-2-2200), modal techniques can be used for dynamic stress analyses in gravity dams, including a simplified response spectrum method and Finite Element Method (FEM), using a response spectrum or acceleration-time record for dynamic input.
In this paper the damage configuration of a concrete gravity dam has been studied. In order to identify the possible crack formation zones a nonlinear model which considers the concrete plastic behavior, was employed to simulate crack propagation within the dam body. The model was numerically implemented in ABAQUS, a FEM analyses code.
The model referred is known as Concrete Damaged Plasticity. It assumes that the main two failure mechanisms are tensile cracking and compressive crushing of the concrete material. The evolution of the yield surface is controlled by two hardening variables, eplc and eplt, linked to failure mechanisms under compression and tension loading, respectively eplt becomes uplt for non-reinforcement concrete. eplc and eplt are referred to as compressive and tensile equivalent plastic strains, respectively, while uplt is knownas "plastic” displacement.
The problem analyzed considers the geometry of Portezuelo del Viento dam, placed in Mendoza, Argentina, in seismic zone 3, according to Argentinian regulation (CIRSOC 103). The design earthquake was described by site-specific accelerations-time records. Prior to the earthquake excitation, the dam is subjected to gravity loading due to its self-weight and to the hydrostatic pressure of the reservoir on the upstream wall.
The results show the damage configuration in the dam, which allow us to identify the possible cracks formation zones and to suggest ways to avoid their development.
In this paper the damage configuration of a concrete gravity dam has been studied. In order to identify the possible crack formation zones a nonlinear model which considers the concrete plastic behavior, was employed to simulate crack propagation within the dam body. The model was numerically implemented in ABAQUS, a FEM analyses code.
The model referred is known as Concrete Damaged Plasticity. It assumes that the main two failure mechanisms are tensile cracking and compressive crushing of the concrete material. The evolution of the yield surface is controlled by two hardening variables, eplc and eplt, linked to failure mechanisms under compression and tension loading, respectively eplt becomes uplt for non-reinforcement concrete. eplc and eplt are referred to as compressive and tensile equivalent plastic strains, respectively, while uplt is knownas "plastic” displacement.
The problem analyzed considers the geometry of Portezuelo del Viento dam, placed in Mendoza, Argentina, in seismic zone 3, according to Argentinian regulation (CIRSOC 103). The design earthquake was described by site-specific accelerations-time records. Prior to the earthquake excitation, the dam is subjected to gravity loading due to its self-weight and to the hydrostatic pressure of the reservoir on the upstream wall.
The results show the damage configuration in the dam, which allow us to identify the possible cracks formation zones and to suggest ways to avoid their development.
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ISSN 2591-3522