Construction joints influence on the stability of an earth dam.

Abstract

This paper presents a study on the influence of construction joints on the stability of an earthfill dam. With this aim, undisturbed samples from the construction joints were taken out, and submitted to triaxial tests to evaluate its shear strength. Toe dam has been built in stages, by the downstream method, with the purpose of tailing disposal from a gold mining. Seven stages already has been concluded and the maximum height reached is 55 meters. At the last stage the dam will be 80 meters height. In the stability analysis, Spencer equilibrium limit and finite element methods were used. Both methods, using either circular and polygonal projection surfaces of sliding, presented similar results, in despite of the distinct approach. The stability analysis showed that polygonal projection surfaces passing through the construction joints and as near as possible of downstream slope may be more critical than circular surfaces of sliding.