13.22 Consider the retaining wall shown in Figure 13.38. The height of the wall is 9.75 m, and the unit weight of the sand backfill is 18.7 kN/m². Using Coulomb's equation, calculate the active force, Pq. on the wall for the following values of the angle of wall friction. Also, comment on the direction and location of the resultant. a. 8' = 14° b. 8' = 21° + Sand y = 18.7 kN/m³ c' = 0 d' = 34° e = 12° 8' (wall friction) e = 10° H= 9.75 m Figure 13.38 © Cengage Learning 2014

The channel section shown is subjected to a vertical shear force of V = 29 kN. Calculate the horizontal shear stress Ta at point A, and the vertical shear stress tR at point B. Assume a = 50 mm, b = 250 mm, tw= 16 mm, t;= 12 mm, d = 74 mm. V | tw Answers: TA = MPa TB = i MPa

A concrete retaining wall 8 m high is supporting a horizontal backfill having a dry unit weight of 16.25kN/m3. The cohesionless soil has an angle of internal friction of 33 degrees and a void ratio 0f 0.65. (Use four decimal places) A. Compute the rankine active force on the wall. B. Compute the rankine active force on the wall if water logging occurs at a depth of 3.5 from the ground surface. C. Compute the location of the resultant active force from the bottom.

Q: The following figure shows a soil system supported by a 3m high retaining wall. This is normally consolidated soil and the wall has been restrained from yielding. Determine the lateral force Po, exerted by the soil system on per unit length of wall. [Yw = 9.81 kN/m³] H = 3m A B С c'=0 $ 20⁰ y = 15 kN/m 3 c'=0 Ø Y sat 20° 18 kN/m3 2m

2- Figure below shows a retaining wall that is restrained from yielding. Determine the magnitude of the lateral earth force per unit length for the following conditions: 1) At-rest force 2) Passive force Also, find the location of the resultant, 7, measured from the bottom of the wall. H (ft) H1 (ft) 71 (lb/fr) 72 (lb/ft³) p'ı q (lb/fr²) 10 5 90 122.4 34 26 100 Surcharge = q Sand c{ = 0 Groundwater table H Sand Y2 (saturated unit weight) có = 0 Frictionless wall

Determine the lateral earth pressure force on the wall (6.0 m height shown in the figure. Draw the stress distribution and locate the location of the resultant force. Sandy soil kN Ye = 20 O = 36.0°

IM No.: IM-C 12.1 Given: H = 12 ft, q = 0, y = 108 lb/ft', c' = (0, and o' 30°. Determine the at-rest lateral earth force per foot length of the wall. Also, find the location of the resultant. Use Eq. (12.4) and OCR = 2. 12.2 Use the following values to determine the at-rest lat- eral earth force per unit length of the wall. Also find the location of the resultant. H = 5 m, H, = 2 m, H, = 3 m, y = 15.5 kN/m', y = 18.5 kN/m', ' = 34°, c' = 0, q = 20 kN/m², and OCR = 1. 12.3 Given the height of the retaining wall, H is 18 ft; the backfill is a saturated clay with o = 0°, c = 500 lb/ft,y = 120 Ib/ft", a. Determine the Rankine active pressure distribution diagram behind the wall. b. Determine the depth of the tensile crack, z.. c. Estimate the Rankine active force per foot length of the wall before and after the occurrence of the tensile crack. 12.4 A vertical retaining wall is 7 m high with a horizontal backfill. For the backfill, assume that y = 16.5 kN/m', ' = 26°, and c' = 18 kN/m2.…

4- A moderately curved channel with a slightly rounded non-cohesive bed material with a diameter of d50 = 25 mm carrying a discharge of 30 m³/s. The longitudinal slope of the channel is 0.001 and the side wall slopes are designed to be 60% of the angle of repose of the bed material Note: Use the Strikler's formula to calculate Manning's value. Use the Swammy and Mittal's formula to estimate the critical shear stress. Use the free board depth of 0.5m. a) Design the channel using the tractive force method for a Boly ratio of 20 b) Design the channel using the most efficient hydraulic section c) Discuss about the channel stability and erosion for both designs in parts a and b Strickler (Chow, 1959) proposed a correlation between the mean diameter of bed material, dso, and the Manning's coefficient as: n = 0.039d¹/6 Swamee and Mittal (1976) proposed an explicit equation to express the Sheild's curve defined as: 50 0.409d² 1/2 (1+0.177d² )¹/¹² T = 0.155+.

4- A moderately curved channel with a slightly rounded non-cohesive bed material with a diameter of d50 = 25 mm carrying a discharge of 30 m³/s. The longitudinal slope of the channel is 0.001 and the side wall slopes are designed to be 60% of the angle of repose of the bed material Note: Use the Strikler's formula to calculate Manning's value. Use the Swammy and Mittal's formula to estimate the critical shear stress. Use the free board depth of 0.5m. a) Design the channel using the tractive force method for a Bo/y ratio of 20 b) Design the channel using the most efficient hydraulic section c) Discuss about the channel stability and erosion for both designs in parts a and b Strickler (Chow, 1959) proposed a correlation between the mean diameter of bed material, deo, and the Manning's coefficient as: n = 0.039d¹/6 Swamee and Mittal (1976) proposed an explicit equation to express the Sheild's curve defined as: T = 0.155+ To 50 0.409d² (1+0.177d²)