Nonlinear Analysis of Concrete Face Rockfill Dam

TLDR

Concrete membrane face rockfill dams are popular but their design remains largely empirical, relying on past experience rather than theory. The study aimed to understand prototype behavior of rockfill dams and identify factors affecting stresses and strains in the face slab and embankment. The authors performed sequential nonlinear analyses using various element types to simulate dam components, compared rockfill embankment behavior under reservoir loading to that of central earth core dams, and examined how valley abutment slopes influence transverse movement and stress development. The analysis showed that creep deformations after reservoir filling dominate stress and deformation development in the upstream face, and that valley abutment slopes significantly affect transverse rockfill movement and stress patterns.

Abstract

The concrete membrane face rockfill dam, in spite of its increasing popularity with construction engineers, is perhaps one structure where the design is still largely empirical and is based on past experience rather than theory. Studies were carried out to understand the prototype behavior of this type of rockfill dam and to identify the various factors influencing the development of stresses and strains in the face slab and the rockfill embankment. Different types of elements are used to simulate the prototype behavior of various components of the dam in the sequential nonlinear analysis and some representative results are presented. The behavior of rockfill embankment on application of reservoir water load in case of face dam is compared with that for the case of central earth core dam. The effect of valley abutment slopes on the movement of rockfill and consequent development of stresses in the embankment in cross‐valley transverse direction is brought out. Creep deformations in the rockfill occurring after filling of reservoir are found to be a major factor governing the development of stresses and deformations in the upstream face membrane.