2. the probability of an earthquake with a magnitude greater than six in a year is 2%. Determine: A. probability that two earthquakes with magnitude greater than six happen in 30 years.

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

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

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

A structural member with a rectangular cross section as shown in the accompanying figure is used to support a load of 2500 N. What type of material do you recommend be used to carry the load safely? Base your calculations on the yield strength and a factor of safety of 2.0.

Repeat Problem 2.14 with the following values: Gs = 2.75, temperature of water = 21C, t = 88 min, and L = 11.7 cm. 2.14 A hydrometer test has the following result: Gs = 2.65, temperature of water = 26 C, and L = 10.4 cm at 45 minutes after the start of sedimentation (see Figure 2.25). What is the diameter D of the smallest-size particles that have settled beyond the zone of measurement at that time (that is, t = 45 min)? Figure 2.25 ASTM 152H type of hydrometer placed inside the sedimentation cylinder (Courtesy of Khaled Sobhan, Florida Atlantic University, Boca Raton, Florida)

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

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