K. Arulanandan et al., CENTRIFUGE STUDY ON VOLUME CHANGES AND DYNAMIC STABILITY OF EARTH DAMS, Journal of geotechnical engineering, 119(11), 1993, pp. 1717-1731
A simplified method of analysis for determining the permanent displace
ment of a clay core in a heterogeneous earth dam subjected to dynamic
excitation is dissussed. Centrifuge studies on three identical models
were used to determine the deformation characteristics of earth dams s
ubjected to earthquakes large enough to produce flow slides. These stu
dies suggest that the failure mode is considerably influenced by the r
eduction in shear strength caused by the void-ratio increase and the s
ubsequent decrease in effective stress at the sand-clay interface. Con
ventional sliding block analysis does not consider this phenomenon. A
simplified method using the concepts of critical-state soil mechanics
is presented that may be used to estimate both the reduced shear stren
gth and the redistributed void-ratio at the interface. Values predicte
d using this method were found to agree well with those observed in th
e centrifuge experiments. By integrating these quantities into Newmark
's sliding block analysis, a better estimate of the permanent displace
ment of an earth dam may be obtained.