2) The following figure in the next page shows the geological and shear wave velocity profile of the Alameda Naval Air Station. Assume the total unit weight of the Old Bay Clay layer is 22.1 kN/m3 , and the groundwater table is at a depth of 7.5 m. Plot the total vertical stress, effective vertical stress, and pore water pressure versus depth for the Alameda Naval Air Station up to the bottom of the Old Bay Clay layer. S Velocity (m/sec) 100 200 300 400 500 600 SAND WATNIOAL F YT = 17 kN/m3 CLAY HOLOCENE BAY MUOI YT = 13 kN/m³ TTAND TO LOAMY SAND MERAITT SANDI YT = 19 kN/m³ ELOAMY SAND, wee beos o SLTY CLAY Vr = 21 kN/m³ SETY CLAY ESTOCENE BAY MUO Old Bay Clay 50 - FI SANDY LOAM GAAVELLY SAND CLAY LOAM TO SLTY CLA CLAY 100 AUSTOCENE ALLUV CLAY LOAM CLAY ECLAY LOAM SAND SANDY CLAY LOAM CRAVELLY SAND SHALE E AN ASTAE 150 Alameda Naval Air Station S-wave velocity profiles with dashed lines representing plus and minus one standard deviation. The statistics are done on the slope (reciprocal velocity) so that some of the limits will not appear symmetrical. Simplified geologic log is shown for correlation with velocities. from U.S. Geological Survey Open-File Report 92-287, "Seismic Velocities and Geologic Logs from Borehole Measurements at Seven STrong-Motion Stations that Recorded the 1989 Loma Prieta Earthquake" Depth (meters)

Plot the variation of total stress, pore water pressure, and effective stress with depth for thesand and clay layers shown in Figure 3, assuming H1 = 6m and H2 = 4m.

A borehole at a site reveals a soil profile shown below. Calculate the effective stress (σ’) in lb/ft2 at the bottom of the soft clay layer. Assume that specific gravity (Gs) of all soil layers is 2.65.