A 2000-lb wheel load is to be supported by aggregate over soil that can withstand a pressure of 1000 lb/sq ft. What depth of aggregate is needed if θ = 40°?

Refer to Figure 5.2. Given: B = L = 1.75 m, Df = 1 m, H = 1.75 m, = 17 kN/m3, c = 0, and = 30. Using Eq. (5.6) and FS = 4, determine the gross allowable load the foundation can carry.

In Problem 7.1, if there was no bedrock present for at least 12.0 ft below the foundation, what would the ultimate bearing capacity be? 7.1 A 7.5 ft wide rough continuous foundation is placed in the ground at 3.0 ft depth. There is bedrock present at 3 ft depth below the bottom of the foundation. The soil properties are c′ = 210 lb/ft2, ϕ′ = 25°, and γ = 115.0 lb/ft3. Determine the ultimate bearing capacity of the foundation.

The tie rods from anchored sheet piles will be connected using a row of anchors, as shown in Figure 18.46a. Here H = 2.0 m, h = 1.25 m, B = 1.5 m, S = 2.5 m, = 32, and = 17.5 kN/m3. The anchor plates are made of 100 mm thick reinforced concrete with a unit weight of 24.0 kN/m3. Determine the ultimate holding capacity of the anchor used Ovesen and Stromanns method.

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.

In concrete work, Fuller and Thompson (1907) suggested that a dense packing of grains can be achieved if the percent finer (p) and grain size (D) are related by the following equation, where n is a constant varying in the range of 0.3-0.6. Dmax is the size of the largest grain within the soil. p=(DDmax)n100 This equation is sometimes used in roadwork for selecting the aggregates. a. For n = 0.5, show that the soil is well graded. b. If n = 0.5 and Dmax = 19.0 mm, find the percentages of gravel, sand, and fines within the soil. Use the Unified Soil Classification System.

A flexible circular footing of radius R carries a uniform pressure q. Find the depth (in terms of R) at which the vertical stress below the center is 20% of q.

State whether the following are true or false. a. Load carrying capacities of timber piles are less than those of steel or concrete piles. b. If the load carried by the pile cross section decreases linearly with depth, the frictional resistance per unit remains the same at all depths. c. The point load is mobilized well before the shaft load. d. Soil-pile friction angle can be greater than the friction angle of the soil . e. Bored piles are high displacement piles.

Consider a continuous foundation of width B = 1.4 m on a sand deposit with c = 0, = 38, and = 17.5 kN/m3. The foundation is subjected to an eccentrically inclined load (see Figure 6.33). Given: load eccentricity e = 0.15 m, Df = 1 m, and load inclination = 18. Estimate the failure load Qu(ei) per unit length of the foundation a. for a partially compensated type of loading [Eq. (6.89)] b. for a reinforced type of loading [Eq. (6.90)]

For the mat in Problem 16.15, what will be the depth, Df, of the mat for FS = 3 against bearing capacity failure? 16.15 Consider a mat foundation with dimensions of 18 m 12 m. The combined dead and live load on the mat is 44.5 MN. The mat is to be placed on a clay with cu = 40.7 kN/m2 and = 17.6 kN/m3. Find the depth, Df, of the mat for a fully compensated foundation.