NEHRP Clearinghouse

Title
Earthquake Induced Permanent Deformations of Embankments.
File
PB284348.pdf
Author(s)
Lee, K. L.
Source
National Science Foundation, Washington, D.C. Applied Science and Research Applications., December 1974, 192 p.
Identifying Number(s)
UCLA-ENG-7498
Abstract
A method is proposed for calculating the permanent deformations at all points within an earth dam due to the effect of an earthquake. The method uses a seismic response analysis to calculate seismic stresses caused by a given time history of base accelerations. Data from laboratory cyclic triaxial tests are used to estimate the permanent strains caused by the induced cyclic stresses. These permanent strains are combined with the cyclic stresses to give a pseudo secant modulus. Sufficient data are obtained to define this pseudo modulus at all locations in the embankment. A finite element computer program is then used to calculate the permanent deformation resulting from this seismic disturbance. This new method was used to calculate the permanent deformations in five older dams, for which actual measurements and other data were available. In all cases the calculated results gave reasonable comparison with observed movements. In addition, several parametric studies were performed to investigate the relative importance of many of the parameters which enter into the analysis. The results of this study suggest that the proposed method, when used with currently obtainable input data, should lead to a useful supplemental or alternative method of assessing the effects likely to result from a strong earthquake near the site of an earth dam, embankment, or slope.
Keywords
Embankments; Earthquake resistant structures; Deformation; Seismic waves; Earth movements; Ground motion; Earthquake engineering; Cyclic loads; Earth dams; Dams; Earthquakes