Q.4/ A normally consolidated (N.C) clay was found to have p-15°, q'= 30°. The soil specimen was tested in a consolidated undrained triaxial test (CU) under a cell pressure 150 kN/m². Determine four of the followings: a) Deviator stress at failure b) Major principal stresses at failure c) Minor principal stresses at failure

Refer to Problem 6.1. Using Eqs. (6.3) and (6.29), estimate the average stress increase (Δσav) below the center of the loaded area between depths of 3 m and 6 m. 6.1 A flexible circular area is subjected to a uniformly distributed load of 150kN/m2 (Figure 6.2). The diameter of the load area is 2 m. Determine the stress increase in a soil mass at points located 3 m below the loaded area at r = 0. 0.4 m, 0.8 m, and 1 m. Use Boussinesq’s solution. Figure 6.2 Increase in pressure under a uniformly loaded flexible circular area