Constitutive Models for Simulation of Field Performance of Dams

Abstract

Numerical models fitting long-term monitoring results represent a useful tool for understanding behavior of dams, especially if unusual performance jeopardizing safety is observed and rehabilitation measures should be suggested. Path-dependent and time-dependent constitutive models suitable for simulating observed behavior of concrete and rockfill dams are described in this paper. For the mechanical part of the solutions, a combined model using path-dependent incrementally linear elasticity in the prepeak regime and theory of plasticity in the peak regime is applied. For the time-dependent part of the solutions, the theory of multiface viscoplasticity is used. Three-surface-viscoplastic flow combined with Feda’s experimental relationships was successfully applied for modeling long-term creep of rockfill undergoing permanent structural changes attributable to grain breakage. By using a synthesis of these models, the reason of unexpectedly large deformations of Sance Rockfill Dam was pinpointed, future performance of the dam predicted, and cracking and hydraulic-fracturing hazard to the clay core estimated. The modeling results provided input for the rehabilitation concept of the dam.