Earthquake response of concrete arch dams: a plastic–damage approach

Abstract

SUMMARYThere are several alternatives to evaluate seismic damage-cracking behavior of concrete arch dams, among which damage theory is the most popular. A more recent option introduced for this purpose is plasticdamage (PD) approach. In this study, a special finite element program coded in 3-D space is developed on the basis of a well-established PD model successfully applied to gravity dams in 2-D plane stress state. The model originally proposed by Lee and Fenves in 1998 relies on isotropic damaged elasticity in combination with isotropic tensile and compressive plasticity to capture inelastic behaviors of concrete in cyclic or dynamic loadings. The present implementation is based on the rate-dependent version of the model, including large crack opening/closing possibilities. Moreover, with utilizing the Hilber-Hughes-Taylor time integration scheme, an incremental-iterative solution strategy is detailed for the coupled dam-reservoir equations while the damage-dependent damping stress is included. The program is initially validated, and then, it is employed for the main analyses of the Koyna gravity dam in a 3-D modeling as well as a typical concrete arch dam. The former is a major verification for the further examination on the arch dam. The application of the PD model to an arch dam is more challenging because the governing stress condition is multiaxial, causing shear damage to become more important than uniaxial states dominated in gravity dams. In fact, the softening and strength loss in compression for the damaged regions under multiaxial cyclic loadings affect its seismic safety.

Quantitative failure metric for gravity dams

“…Indeed dams have historically provided a framework of applications for innovative numerical methods, such as the finite difference one or the finite element method . Although linear elastic analysis prevailed for a long time due to limited computational capabilities, new advances in hardware has lead to innovative nonlinear transient analysis models . Dam‐foundation interaction and also modeling the far‐end boundaries of the semi‐infinite medium were investigated by other researchers .…”

Modification of Concrete Damaged Plasticity model. Part I: Modified plastic potential

“…The Drucker-Prager type potentials are commonly used to cover observed performance of concrete structures, compare [1][2][3][4][5][6][7] among others. They characterize properly compressive behavior of the material though they fail to model its tensile properties.…”

“…Basic models for concrete and soil use Drucker-Prager type functions as both the yield condition and the plastic potential [1][2][3][4][5][6][7]. The experiments showing deviation of plastic strain rate tensor from the gradient of yield function are scarce, compare [8] for soils, however it is frequently assumed that the flow rule should be non-associative [5,6,8].…”

“…Material damage evolves along with the plastic strain growth; however the coupling between damage and plasticity is weak. The model has been continuously modified to better fit experimental data [7,10,11]. The main features taken into consideration by the researchers are the hardening rule and the failure criterion [10,11].…”

Seismic Damage Analysis of Concrete Gravity Dam Based on Wavelet Transform

“…Lee and Fenves [1,2] proposed the plastic damage constitutive model of concrete and simulated failure processes of concrete structures as well as the Koyna dam under earthquake and acquired the consistent results with the actual earthquake damage. A lot of results have been achieved in analyzing the damage of concrete dams under the action of earthquake [3][4][5], in which the plastic damage models were used. To assess the structural damage state simulated using numerical methods, many kinds of damage indexes have been proposed [6][7][8][9].…”