Question 11.13: In Fig. 11.21, assume at Boring B-25 that the uppermost soil...

In Fig. 11.21, assume at Boring B-25 that the uppermost soil layer (silt, silty sand, and peat layer) extends from elevation -2 to -5 m and the light gray silty sand layer extends from elevation -5 to -8 m. It is anticipated that the site will be subjected to significant earthquake shaking and that these two layers will liquefy during the earthquake. Use k = 0.4 and \phi_{w}=15^{\circ} for the 3 m thick silt-peat layer and use k = 0.5 and \phi_{w}=20^{\circ} for the 3 m thick light gray silty sand layer. Using the data from Prob. 11.5, determine the downdrag load on the pier for liquefaction of the two layers.