This paper investigates the impact of the following five assumptions on the accuracy of Newmark seismic deformation analysis applied to geosynthetic cover systems: i) the potential failure mass is noncompliant; 22) the dynamic response of the potential failure mass is uncoupled from displacement (slip); iii) permanent displacements accumulate in only one direction; iv) vertical ground motions do not influence permanent displacement; and v) the yield acceleration is constant. Information presented in the literature indicates the impact of the assumption of a noncompliant failure mass and the assumption of a seismic response uncoupled from displacement is insignificant for typical geosynthetic cover systems. The results of computer analyses indicate that the effects of two-way sliding and vertical ground motions can, in most practical cases, be neglected. However, the assumption of a constant yield acceleration, when based on residual (or large displacement) shear strength, may result in calculated displacements that are significantly larger than those calculated using a yield acceleration that degrades with accumulated displacement from a peak value to a residual, or large displacement, value. Overall, results of this investigation indicate that conventional Newmark analyses based upon residual shear strength yield conservative results when applied to geosynthetic cover systems.
ASJC Scopus subject areas
- Geotechnical Engineering and Engineering Geology