Seismic response evaluation of strip footing on geogrid‑reinforced slope

摘要

Changes in the mechanical properties of the soil due to soil improvements cause a change in the nature of the waves passing through it and thus affect its seismic response. To evaluate this issue, the numerical model is first validated, using the recorded information of the Gilroy region. Then, the seismic response of the strip footing located on the geogrid-reinforced slope crest is investigated and compared with the case of non-reinforced one. To assess the seismic response, three earthquakes, including Loma Prieta 1989, Kobe 1995, and Tabas 1978, are applied to the bedrock as incident waves. Investigations are performed through two-dimensional nonlinear analysis using finite element method. The coupled effect of variation in soil characteristics due to reinforcement and irregular topography is considered to estimate the seismic response of the problem. The results are shown using acceleration time-histories, acceleration response spectra, and Fourier amplitude spectra on the soil surface. The Amplification Factor (AF) of Peak Ground Acceleration (PGA) is also presented at different points of the slope and its surrounding areas. The results show the significant effect of soil reinforcement on the seismic response of the slope, which should be considered to apply the design spectra proposed by building codes and standards in such conditions.