Q. No. 12: A roadway sign that weighs P, = 9 kN is supported by a structural pipe with an outside diameter of 325 mm and a wall thickness of 12.5 mm. Wind pressure on the sign creates a resultant force of P, 21 kN, acting as shown in the Figure. Using length dimensions of a = 5.2 m and b = 6.4 m, analyse using the concepts of stresses under combined loadings to determine (a) the normal and shear stresses at point H. (b) the normal and shear stresses at point K.

Use Eq. (6.14) to determine the stress increase () at z = 10 ft below the center of the area described in Problem 6.5. 6.5 Refer to Figure 6.6, which shows a flexible rectangular area. Given: B1 = 4 ft, B2 = 6 ft, L1, = 8 ft, and L2 = 10 ft. If the area is subjected to a uniform load of 3000 lb/ft2, determine the stress increase at a depth of 10 ft located immediately below point O. Figure 6.6 Stress below any point of a loaded flexible rectangular area

Refer to Figure 10.46. A flexible circular area of radius 6 m is uniformly loaded. Given: q = 565 kN/m2. Using Newmarks chart, determine the increase in vertical stress, z, at point A. Figure 10.46

Refer to Figure 8.24. Determine the vertical stress increase, , at point A with the following values: q1 = 100 kN/m x1 = 3 m z = 2 m q2 = 200 kN/m x2 = 2 m FIG. 8.24 Stress at a point due to two line loads

Repeat Problem 10.12 for q = 700 kN/m2, B = 8 m, and z = 4 m. In this case, point A is located below the centerline under the strip load. 10.12 Refer to Figure 10.43. A strip load of q = 1450 lb/ft2 is applied over a width with B = 48 ft. Determine the increase in vertical stress at point A located z = 21 ft below the surface. Given x = 28.8 ft. Figure 10.43

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 Figure 10.48. If R = 4 m and hw = height of water = 5 m, determine the vertical stress increases 2 m below the loaded area at radial distances where r = 0, 2, 4, 6, and 8 m. Circular contact area of radius R on the ground surface Figure 10.48

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.

For the same line loads given in Problem 10.8, determine the vertical stress increase, z, at a point located 4 m below the line load, q2. Refer to Figure 10.41. Determine the vertical stress increase, z, at point A with the following values: q1 = 110 kN/m, q2 = 440 kN/m, x1 = 6 m, x2 = 3 m, and z = 4 m. Figure 10.41

A planned flexible load area (see Figure P7.2) is to be 3 m × 4.6 m and carries a uniformly distributed load of 180 kN/m2. Estimate the elastic settlement below the center of the loaded area. Assume that Df = 2 m and H = . Use Eq. (7.4).