Fig. 15
From: Influence of P-wave oblique incidence on seismic response of helical piles in soft soil sites

Double helical blade for PGA = 0.1 g (El-Centro wave).
From: Influence of P-wave oblique incidence on seismic response of helical piles in soft soil sites

Double helical blade for PGA = 0.1 g (El-Centro wave).