Numerical investigation and estimation of active earth thrust on gravity retaining walls under seismic excitation.

Earthquakes can create severe damage to retaining structures. A numerical study is carried out to understand the seismically induced active earth pressure force on free-standing gravity retaining walls. Dynamic behavior in terms of acceleration amplification/deamplification, deformation mechanism, and earth pressure force are examined. Further, the influence of input peak ground acceleration (PGA), retaining wall height, Young's modulus of the wall, relative density of soil, and soil-structure interaction on total active earth pressure force (P ae) are investigated. The results show that P ae decreases until PGA value is around 0.55 g and later increases for higher values. The primary cause for this response is the loss of wall-soil interaction due to the overturning effect, which dominates until PGA approaches 0.55 g. Also, the generation of failure wedges causes an increase in P ae after 0.55 g. Sensitivity analysis concludes that P ae is highly sensitive to PGA, wall height, and soil-structure interaction. Based on regression analysis, an equation is proposed for the total active thrust. Later, the accuracy of the equation is confirmed by comparing it with the response of FE analysis and established study. This study contributes to developing an equation that is anticipated to provide total active thrust at the initial design stage under comparable work environment. [Display omitted] • Non-linear amplification of acceleration up to k h = 0.55 followed by deamplification. • Overturning mode of wall failure is dominant with formation of multiple failure planes in backfill. • P ae decreases with increase in k h up to 0.55 followed by increase till k h reaches 1.2 • Proposed equation for P ae considering earthquake, wall, soil, and interface characteristics. • Useful to evaluate P ae at initial design stage under similar work environment. [ABSTRACT FROM AUTHOR]