Refer to Problem 12.6. Given: cv = 2.8 × 10– 6 m2 /min. How long will it take for 60% consolidation to occur?
> Figure 14.12 shows a frictionless wall with a sloping granular backfill. Given: H = 7 m, = 12°, ’ = 288, and = 18.6 kN/m3 . Determine the magnitude of active pressure, ’ , at the bottom of the wall. Determine the Rankine active force, Pa, per u
> For the partially submerged backfill in Problem 14.13 (Figure 14.36), determine the Rankine passive force per unit length of the wall and the location of the resultant.
> For a given sand, the maximum and minimum void ratios are 0.78 and 0.43, respectively. Given Gs = 2.67, determine the dry unit weight of the soil in kN/m3 when the relative density is 65%.
> A retaining wall is shown in Figure 14.36. For each problem, determine the Rankine active force, Pa, per unit length of the wall and the location of the resultant.
> A retaining wall is shown in Figure 14.36. For each problem, determine the Rankine active force, Pa, per unit length of the wall and the location of the resultant.
> A retaining wall is shown in Figure 14.36. For each problem, determine the Rankine active force, Pa, per unit length of the wall and the location of the resultant.
> Consider the clay specimen in Problem 13.8. A consolidated-undrained triaxial test was conducted on the same clay with a chamber pressure of 15 lb/in2 . The pore pressure at failure is (ud)f = 4.8 lb/in2 . What would be the major principal effective str
> In a consolidated-drained triaxial test on a clay, the specimen failed at a deviator stress of 18 lb/in2 . If the effective stress friction angle is known to be 31°, what was the effective confining pressure at failure?
> For a normally consolidated clay specimen, the results of a drained triaxial test are as follows. Chamber-confining pressure = 125 kN/m2 Deviator stress at failure = 175 kN/m2 Determine the soil friction angle ’.
> The relationship between the relative density, Dr, and the angle of friction, ’, of a sand can be given as ’ 5 28 1 0.18 Dr (Dr in %). A drained triaxial test was conducted on the same sand with a chamber-confining pressure of 150 kN/m2 . Calculate the
> Refer to Figure 13.62. Shear strength parameters are needed for the design of a foundation placed at a depth of 2 m in the silty sand layer. Soils collected from this sand were compacted in the direct shear mold (diameter 5 63.5 mm) at the same dry unit
> During a subsoil exploration program, undisturbed normally consolidated silty clay samples were collected in Shelby tubes from location A as shown in Figure 13.62. Following are the results of four drained, direct shear tests conducted on the clay samp
> For a dry sand specimen in a direct shear test box, the following are given. Size of specimen: 2.5 in. ×2.5 in. × 1.25 in. (height) Angle of friction: 33° Normal stress: 28 lb/in2 Determine the shear force required to cause failure.
> Refer to Problem 3.18. Given that the borrow pit has a moisture content of 11% and Gs = 2.7, determine: Moist unit weight of the borrow soil Degree of saturation of the borrow soil Moist unit weight of the compacted backfill
> Refer to the clay soil in Figure 13.63. If the natural moisture content is 28%, estimate the undrained shear strength of remolded clay using the relationships given in Table 13.5 by Leroueil et al. (1983) Terzaghi et al. (1996)
> A 15 m thick normally consolidated clay layer is shown in Figure 13.63. The liquid limit and plastic limit of the soil are 39 and 20, respectively. Using Eq. (13.53) given by Skempton (1957), estimate the undrained cohesion at a depth of 11 m below the
> Consider the specimen in Problem 13.1b. What are the principal stresses at failure? What is the inclination of the major principal plane with the horizontal?
> Results of two consolidated-drained triaxial tests on a clayey soil are as follows. Using the failure envelope given in Example 13.18 (q’ =  1 p’ tan ), determine the following (do
> Undisturbed samples from a normally consolidated clay layer were collected during a field exploration program. Drained triaxial tests showed that the effective friction angle at ’ = 28°. The unconfined compressive strength, u, of a similar specimen was
> A consolidated-undrained triaxial test was conducted on a dense sand with a chamber-confining pressure of 20 lb/in2 . Results showed that ’ = 24° and = 31°. Determine the deviator stress and the pore water pressure at failure. If the sand were loose,
> If a consolidated-drained test is conducted on the clay specimen of Problem 13.15 with the same chamberconfining pressure of 150 kN/m2 , what would be the deviator stress at failure?
> The shear strength of a normally consolidated clay can be given by the equation f = ’ tan 27°. Following are the results of a consolidated-undrained test on the clay. Chamber-confining pressure = 150 kN/m2 Deviator stress at failure = 120 kN/m2 Deter
> A clay sample was consolidated in a triaxial test chamber under an all-around confining pressure of 22 lb/in2 . The sample was then loaded to failure in an undrained condition by applying an additional axial stress of 28 lb/in2 . A pore water pressure se
> Consider the triaxial tests in Problem 13.12. What are the normal and shear stresses on a plane inclined at 40° to the major principal plane for Specimen I? What are the normal and shear stresses on the failure plane at failure for Specimen II?
> Refer to Figure 3.13. After the construction of a concrete retaining wall, backfill material from a nearby borrow pit was brought into the excavation behind the wall and compacted to a final void ratio of 0.8. Given that the soil in the borrow pit has a
> The results of two consolidated-drained triaxial tests on a clay are given here. Calculate the shear strength parameters of the soil.
> A consolidated-drained triaxial test was conducted on a normally consolidated clay with a chamber pressure, 3 = 25 lb/in2 . The deviator stress at failure is (ud)f = 33 lb/in2 . Determine the following. The angle of friction ’ The angle u that the f
> Following are the results of consolidated-undrained triaxial tests on undisturbed soils retrieved from a 4 m thick saturated clay layer in the field (sat = 19 kN/m3 ). Estimate graphically the Mohr–Coulomb shear stren
> The following data are given for a direct shear test conducted on dry silty sand: Specimen dimensions: 63 mm × 63 mm × 25 mm (height) Normal stress: 105 kN/m2 Shear force at failure: 300 N Determine the angle of friction, ’. For a normal stress of 18
> The laboratory consolidation data for an undisturbed clay specimen are as follows. e1 = 1.1 ’ 1 = 1 ton/ft2 e2 = 0.9 ’ 2 = 3 ton/ft2 What is the void ratio for a pressure of 3.5 ton/ft2 ? (Note: ’ c = 0.8 ton/ft2 .)
> The coordinates of two points on a virgin compression curve are as follows. e1 = 0.82 ’ 1 = 2500 lb/ft2 e2 = 0.70 ’2 = 4000 lb/ft2 Determine the void ratio that corresponds to a pressure of 6000 lb/ft2 .
> Refer to Figure 12.42. Given: H1 = 5 ft, H2 = 7 ft, H3 = 6 ft, and Ds = 3000 lb/ft2 . Also, Clay: e = 1.1, Gs = 2.72, LL = 45 Sand: e = 0.58, Gs = 2.65 Estimate the primary consolidation settlement if the pre-consolidation pressure is 3500 lb/ft2 .Ass
> Refer to Figure 12.42. Given: H1 = 2.5 m, H2 = 2.5 m, H3 = 3 m, and  = 100 kN/m2 . Also, Sand: e = 0.64, Gs = 2.65 Clay: e = 0.9, Gs = 2.75, LL = 55 Estimate the primary consolidation settlement of the
> Figure 12.42 shows a soil profile. The uniformly distributed load on the ground surface is Ds. Given:  = 1000 lb/ft2 , H1 = 8 ft, H2 = 15 ft, and H3 = 17 ft. Also, Sand: dry = 110 lb/ft3 , ï
> The results of a laboratory consolidation test on a clay specimen are the following. Given the initial height of specimen 5 0.748 in., Gs = 2.68, mass of dry specimen = 95.2 g, and area of specimen = 4.91 in2: Plot the e-log â&
> Refer to Problem 3.16. Determine the weight of water, in lb, that will be in 2.5 ft3 of the soil when saturated.
> Repeat Problem 12.2 using the following values
> Foundation engineers are often challenged by the existence of soft compressible soils at the construction site. Figure 12.44 shows a soil profile with a silty sand ( = 17 kN/m3 ; sat = 19.2 kN/m3 ) underlain by high pl
> The following are the results of a consolidation test. Plot the e-log ’ curve. Using Casagrande’s method, determine the preconsolidation pressure. Calculate the compression index, Cc, from the lab
> Refer to Figure 12.43. Given that B = 1 m, L = 3 m, and Q = 110 kN, calculate the primary consolidation settlement of the foundation.
> A normally consolidated clay layer is 3 m thick (one-way drainage). From the application of a given pressure, the total anticipated primary consolidation settlement will be 80 mm. What is the average degree of consolidation for the clay layer when the se
> A 3 m thick layer of saturated clay (two-way drainage) under a surcharge loading underwent 90% primary consolidation in 100 days. The laboratory test’s specimen will have two-way drainage. Find the coefficient of consolidation of clay for the pressure r
> The time for 50% consolidation of a 25 mm thick clay layer (drained at top and bottom) in the laboratory is 225 s. How long (in days) will it take for a 2 m thick layer of the same clay in the field (under the same pressure increment) to reach 50% consol
> For a laboratory consolidation test on a clay specimen (drained on both sides), the following were obtained. Thickness of the clay layer = 25 mm ’ 1 = 200 kN/m2 e1 = 0.73 ’ 2 = 400 kN/m2 e2 = 0.61 Time for 50% consolidation (t50) = 2.8 min Determi
> For a normally consolidated clay, the following are given. ’ o = 2 ton/ft2 e = eo = 1.21 ’ o + ’ = 4 ton/ft2 e = 0.96 The hydraulic conductivity k of the clay for the preceding loading range is 1.8 3 1024 ft/day. How long (in days) will it ta
> The time for 50% consolidation of a 1 in. thick clay layer (drained at top and bottom) in the laboratory is 2 min, 20 s. How long (in days) will it take for an 8 ft thick layer of the same clay in the field (under the same pressure increment) to reach 30
> The moist unit weights and degrees of saturation of a soil are given in the table. Determine: e Gs
> The coordinates of two points on a virgin compression curve are as follows. e1 = 1.7 ’ 1 = 150 kN/m2 e2 = 1.48 ’ 2 = 400 kN/m2 Determine the coefficient of volume compressibility for the pressure range stated. Given that cv = 0.002 cm2 /s, dete
> Following are the relationships of e and ’for a clay soil. For this clay soil in the field, the following values are given: H = 4.5 ft, ’ o = 0.7 ton/ft2 , and &a
> Following are the results of a laboratory consolidation test on a sample of undisturbed clay obtained from the field The height of the specimen at the beginning of the test was 1.9 cm, and the diameter was 6.35 cm. The mass of the dry specimen was 91 g
> A shallow foundation supported by a silty sand is shown in Figure 11.6. Given: Length: L = 3 m Width: B = 3 m Depth of foundation: Df = 1.5 m Thickness of foundation: t = 0.25 m Load per unit area: = 150 kN/m2 Ef = 15 3 106 kN/m2 The silty sand has t
> A rigid, reinforced concrete foundation is subjected to a column load of 87,000 lb. The foundation plan measures 8 ft × 8 ft and rests on 21 ft (5 H’) of layered soil underlain by rock. The soil layers have the following ch
> A vertical column load, P = 600 kN, is applied to a rigid concrete foundation with dimensions B = 1 m and L = 2 m, as shown in Figure 11.11. The foundation rests at a depth Df = 0.75 m on a uniform dense sand with the following properties. Average modulu
> Repeat Problem 10.8 with the following data. q1 = 300 kN/m x1 = 4 m q2 = 260 kN/m x2 = 3 m z = 3 m
> Refer to Figure 10.50. Determine the vertical stress increase, s, at point A with the following values. q1 = 75 kN/m x1 = 2 m q2 = 300 kN/m x2 = 3 m z = 2 m
> Point loads of magnitude 8.9, 17.8, and 26.7 kN act at A, B, and C, respectively (Figure 10.49). Determine the increase in vertical stress at a depth of 3 m below point D. Use Boussinesq’s equation.
> The moist unit weight of a soil is 112.32 lb/ft3 at a moisture content of 10%. Given Gs = 2.7, determine: e Saturated unit weight Answer / /
> Repeat Problem 10.5 for the soil element shown in Figure 10.48.
> A soil element is shown in Figures 10.47. Determine the following. Maximum and minimum principal stresses Normal and shear stresses on the plane AB Use the pole method.
> Repeat Problem 10.3 for the soil element shown in Figure 10.46.
> Using the principles of Mohr’s circles for the soil element shown in Figure 10.45, determine the following. Maximum and minimum principal stresses Normal and shear stresses on the plane AB
> Refer to Figure 10.57. For the linearly increasing vertical loading on an infinite strip of width 5 m, determine the vertical stress increase, z, at A.
> Refer to Figure 10.56. 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.
> Figure 10.56 shows the schematic of a circular water storage facility resting on the ground surface. The radius of the storage tank is R = 2.5 m and the maximum height of water is hw = 4 m. Determine the vertical stress increase, ï
> Refer to the flexible loaded rectangular area shown in Figure 10.55. Using Eq. (10.42), determine the vertical stress increase below the center of the area at a depth of 3.5 m.
> Repeat Problem 10.1 for the element shown in Figure 10.44.
> The plan of a flexible rectangular loaded area is shown in Figure 10.55. The uniformly distributed load on the flexible area, a, is 100 kN/m2 . Determine the increase in the vertical stress, z, at a depth of z = 2 m be
> A soil has w = 18.2%, Gs =2.67, and S =80%. Determine the moist and dry unit weights of the soil in lb/ft3.
> Refer to Figure 10.54. The circular flexible area is uniformly loaded. Given q = 300 kN/m2 and using Newmark’s chart, determine the vertical stress increase z at point A.
> Figure 10.31 shows a flexible circular area of radius R = 3 m. The uniformly distributed load on the circular area is 96 kN/m2. Calculate the vertical stress increase at r = 0, 0.6, 1.2, 2.4, and 3.6 with z = 1.5 m.
> Consider a circularly loaded flexible area on the ground surface. Given the radius of the circular area R = 4 m and the uniformly distributed load q = 200 kN/m2 , calculate the vertical stress increase, z, at points 1.5, 3, 6, 9, and 12 m below the gro
> Figure 10.53 shows an embankment load for a silty clay soil layer. Determine the vertical stress increase at points A, B, and C.
> An earth embankment diagram is shown in Figure 10.52. Determine the stress increase at point A due to the embankment load.
> Repeat Problem 10.12 for B = 3 m, q = 60 kN/m2, x = 1.5 m, and z = 3 m.
> Refer to Figure 10.17. Given: B = 3.7 m q = 16.8 kN/m2 x = 2.7 m z = 1.5 m. Determine the vertical stress increase, z, at Point A.
> Refer to Figure 10.51. Due to the application of line loads q1 and q2, the vertical stress increase, z, at A is 30 kN/m2. Determine the magnitude of q2.
> Refer to Figure 10.50. Given: q1 = 10.9 kN/m x1 = 2.45 m x2 = 1.22 m z = 0.9 m If the vertical stress at point A due to the loading is 1.7 kN/m2, determine the magnitude of q2.
> A soil element is shown in Figure 10.43. Determine the following. Maximum and minimum principal stresses Normal and shear stresses on the plane AB Use Eqs. (10.3), (10.4), (10.6), and (10.7).
> A soil has e = 0.75, w = 21.5%, and Gs = 2.71. Determine: Moist unit weight (lb/ft3) Dry unit weight (lb/ft3) Degree of saturation (%)
> Refer to Figure 9.5a. Given: H1 = 1 m, H2 = 2 m, h = 1.2 m, void ratio of sand (e) = 0.55, specific gravity of soil solids (Gs) = 2.68, area of the tank = 0.5 m2 , and hydraulic conductivity of sand = 0.1 cm/s. What is the rate of upward seepage? If h 5
> Refer to Figure 9.5a. If H1 = 0.6 m, H2 = 1 m, h 5 0.4 m, sat = 18.6 kN/m3 , hydraulic conductivity of sand (k) = 0.12 cm/s, and area of tank = 0.45 m2 , what is the rate of upward seepage of the water (m3 /min)?
> Refer to Problem 9.6. It is required to make an open excavation of 18 ft in the saturated clay. To avoid heaving, the cut will be filled with water similar to that shown in Figure 9.6. What should be the height of water, h, in the excavation?
> An exploratory drill hole was made in a stiff saturated clay (see Figure 9.28). The sand underlying the clay was observed to be under artesian pressure. Water in the drill hole rose to a height of 18 ft above the top of the sand layer. If an open excavat
> A sand has Gs = 2.68. Calculate the hydraulic gradient that will cause boiling for e = 0.4, 0.5, 0.6, and 0.7. Plot a graph for icr versus e.
> Refer to the soil profile shown in Figure 9.27. Calculate the variation of , u, and ’ with depth. If the water table rises to the top of the ground surface, what is the change in the effective stres
> Refer to Figure 9.26. Calculate , u, and ’ at A, B, C, and D for the following cases, and plot the variations with depth. (Note: e = void ratio,  = moisture content, Gs = specific
> Refer to Figure 9.26. Calculate , u, and ’ at A, B, C, and D for the following cases, and plot the variations with depth. (Note: e = void ratio,  = moisture content, Gs = specific
> Figure 9.31 shows a concrete dam. Consider Case 1 without the sheet pile and Case 2 with the sheet pile along the upstream side. Draw flow nets for both cases. Determine the value of q/k for both cases. (Note: q= m3/s/m; k = m/s.) Determine the factor of
> Determine the factor of safety against heave on the downstream side of the single-row sheet pile structure shown in Figure 9.30. Use the following soil and design parameters: H1 = 7 m, H2 = 3 m, thickness of permeable layer (T) = 12 m, design depth of pe
> Results of a sieve analysis for Soils A, B, and C are given below. To obtain a more representative sample for further geotechnical testing, a ternary blend was created by uniformly mixing 8000 kg of each soil. If a sieve analysis is conducted on the mi
> Repeat Problem 2.3 with the following data.
> Design a clamper to perform the function indicated in Fig. 2.184.
> For the network of Fig. 2.183: a. Calculate 5t. b. Compare 5t to half the period of the applied signal. c. Sketch vo.
> Sketch vo for each network of Fig. 2.182 for the input shown.
> Sketch vo for each network of Fig. 2.181 for the input shown.
> Sketch iR and vo for the network of Fig. 2.180 for the input shown.
> Determine vo for each network of Fig. 2.179 for the input shown.
> Determine vo for each network of Fig. 2.178 for the input shown.
> Determine vo for each network of Fig. 2.177 for the input shown.
> Determine vo for each network of Fig. 2.176 for the input shown.
