ABSTRACT
For earthquake-resistant design of earth retaining structures like retaining walls, bridge abutments,
quay walls, anchored bulk-heads, and braced excavations, the knowledge of seismic
earth pressures is essential to minimize the devastating effects of earthquake hazards. During
earthquake shaking, soil pressures that act on retaining structures include both static and
dynamic components. Dynamic forces vary as the shaking proceeds and reflect not only the
type of wall and soil retained but also complex structure-interaction effects that in general
are difficult to analyze. For example, motion components that are close to the natural period
of the soil structure system can induce very large transient pressures. Also, phase difference
along the length of the retaining structure may induce significant shear forces and bending
moments. In practice, however,most walls are designed using simplified pseudostatic methods.
The approach is to determine all static forces, along with psedostatic seismic forces, and
proceed with conventional stability checks for overturning, sliding, bearing capacity, and overall
stability. In this paper, differentmethods to calculate seismic forces and their point of application
are reviewed, analysis of retaining wall for liquefied and weakened backfill soil is discussed and
methods for earthquake analysis of restrained and temporary braced walls are presented.
Keywords: Earth retaining structures, Seismic active earth pressure, Seismic passive earth pressure, Pseudo-static analysis, Pseudo-dynamic analysis, Displacement based analysis.
