A STUDY OF CRACKS IN EMBANKMENT DAMS

Abstract

Although cracks in'embankment dam have caused trouble since the earliest days of dam building, little published information on the subject was available before 1950. Only then that cracking in embank-ment dams had received more attention by both researchers and practi-tioners, Nowadays, it is well recognised that cracks have been common in all types of well constructed embankment dams and they have developed in. impervious sections or cores constructed of almost all types of soils. Differential settlements have been the major cause and among the various factors influencing cracking, the following have been the most important: i) Valley shape, variation in thickness and compressibility of overburden along the foundation ii) Embankment soil type, and iii) Construction water content Prediction of cracking potential has been one of the most important aspects in the design. Although there have been several dependable approaches in dealing with the prediction of cracking, their application to practical problems would still be limited. The only reliable theoritical approach in this aspect is the application of the Finite Element Method to computation ofstress and strain within the embankment on any type of foundations. Cracking in itself is not dangerous under many field conditions, as suggested by the excellent performance of many embankment dams known to have cracks in them, nevertheless, the necessity to guard against cracking is obvious for the sake of safety of the dams, since severe damage which may lead to complete failure by piping can be initiated by concentrated leaks through cracks. In this study, the various important aspects of the subject are discussed and described in some detail. with the purpose to seek a better and conclusive understanding, necessary for an optimum design of an embankment dam.