On the Stress Analysis and the Stability Computation of Earth Embankments. Part I Stress Distribution in Earth Embankments

Abstract

As the fundamental research for the stability analysis in the embankment design, the stress distribution and the character of pore pressures in earth embankments are investigated in this paper. In the author's stability analysis, the residual strength reserved in the embankment at the natural state is estimated, and then the externally applied forces and the internally acting pore pressures are computed. Thus, the stability of the earth embankment is checked by comparing these forces with each other. Part I is described concerning the stress distribution in earth embankments. First, scrutinizing several conventional studies ever presented, it is pointed out that there exist some inaccuracies or contradictions in the substantial problem of determining the stability of the structure, although they have the remarkable importance partially. Then, in order to modify these inconsistencies and to develop their substances, the author introduces the concept of the residual strength in the embankment and designates the stress distribution at rest as the function of compaction. Therefore, the coefficient of earth pressure at rest or of compaction is treated as a factor of importance to estimate the stress distribution in this analytical solution. The character of pore pressures in earth embankments is studied in Part II, to investigate their effects on the stability of the structure. In this part of the paper, stability analyses during the fill construction and for rapid-drawdown of the reservoir are described, illustrating some numerical calculations, respectively. The failure of the earth embankment due to these pore pressures is still considered as progressive one. In the result, it is shown that such pore pressures have a serious effect on the stability of the earth embankment, whereupon the method of reasonable design should be established.