A site is underlain by two layers of normally consolidated clayey sand. The unit weights of the top layer are 19 and 21 kN/m3 and the layer is one meter thick. The unit weights of the bottom layer are 20 and 22 kN/m3 and the layer is 6 meters thick Below the bottom layer lies bedrock. The water table is located 2 meters below the ground surface. The top layer soil has an effective stress friction angle of 38 degrees, a cohesion intercept of 20 kPa, and an undrained strength of 160 kPa. The bottom layer soil has an effective stress friction angle of 33 degrees, a cohesion intercept of 10 kPa, and an undrained strength of 120 kPa. Point A is located 5 meters underground. All layers have a lateral stress ratio of 0.5. a. Draw the profile neatly (use a ruler) and use a spreadsheet software (like MS Excel) to plot the vertical effective stress vs. depth. Plot the stress (kPa) in the x axis and the depth (in meters) in the y axis, increasing downwards.
b. Determine the shear stress on a plane that crosses point A and is oriented 35 degrees from the horizontal. If you draw a Mohr Circle, then use a scale of 10 kPa 1 cm. Draw the circle PERFECTLY
c. Determine the drained strength of the soil at point A, on the plane described in problem 2b. C.