Stresses in Soil Mass: Mohr's Circle 131.6 kPa 53.6 kPa 315.2 kPa 315.2 kPa 131.6 kPa 2. Find Normal and Shear Stress at Failure Plan A-B. Enter your answer to three significant figures. (1 decimal place) Shear Strength of Soil The following are the results of two consolidated-drained triaxial tests on a clay: Test I: 03 = 140 kN /m²; ({failure) = 368 kN /m² Test II: 03 = 286 kN /m²; o1(failure) = 701 kN /m² Determine the shear strength parameters; that is, c' and o'. (Enter your answers to three significant figures.) d' kN /m²

A soil element beneath a pave ment experiences principal stress rotations when the wheel load, W, passes over it and moves away, as shown in Figure 10.51. In this case, the wheel load has passed over points A and B and is now over point C. The general state of stress at these points is similar to the one shown by a stress block at point D. The phenomenon of principal stress rotation influences the permanent deformation behavior of the pavement layers. Investigate how the magnitude and the orientations of the principal stresses vary with distance from the point of application of the wheel load. Consider the case shown in Figure 10.51. An unpaved aggregate road with a thickness of 610 mm and unit weight of 19.4 kN/m3 is placed over a soil subgrade. A typical single-axle wheel load, W = 40 kN, is applied uniformly over a circular contact area with a radius of R = 150 mm (tire pressure of 565 kN/m2). The horizontal and shear stresses at each point are calculated from a linear elastic finite element analysis for a two-layer pavement and are presented in the following table. a. Use Eq. (10.28) to calculate the vertical stress increases at soil elements A, B, and C that are located at radial distances 0.457,0.267, and 0 m, respectively, from the center of the load. Determine the total vertical stress (y) due to wheel load, the overburden pressure at each point, and enter these values in the table. b. Use the pole method to determine the maximum and minimum principal stresses (1 and 3) for elements A, B, and C. Also determine the orientation (s) of the principal stress with respect to the vertical. Enter these values in the table. c. Plot the variations of 1 and s, with normalized radial distance, r/R, from the center of loading.

Refer to Figure 10.42. Due to application of line loads q1 and q2, the vertical stress increase at point A is 58 kN/m2. Determine the magnitude of q2. Figure 10.42

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