Chapter 13, Problem 13.6P

A retaining wall 6 m high supports cohesionless soil having a dry density of 1600 kg/m³, angle of resistance 32 and void ratio of 0.68. The surface of the soil is horizontal and level with the top of the wall. Neglecting wall friction and using Rankine’s formula for active pressure of a cohesionless soil. 1. Determine the nearest value of the total earth thrust on the wall in KN per lineal meter if the soil is dry.  a. 73.1 b. 86.7 c. 62.4 d. 98.1 2. Find the nearest value of the thrust on the wall in KN per lineal meter if owing to inadequate drainage, it is waterlogged to a level of 3.5 m below the surface. a. 112 b. 171 c. 147 d. 153 3. Find at what height above the base of the wall the thrust acts during the waterlogged condition. a. 2.21 m b. 2.00 m c. 1.74 m d. 1.42 m

16 Determine the total active thrust, in kN/m, for a retaining wall (height 5.60 m.) with horizontal backfill given the following properties: Unit weight = 17.42 kN/m3, Angle of internal friction = 32°, Cohesion = 11.76 kPa, and Surcharge = 9.32 kPa. Round off to two decimal places.

For a smooth vertical wall retaining a granular backfill inclined at an angle of a = 15 ° , check whether Eqs . ( 16.70 ) and (16.72 ) ( or Tables 16.9 and 16.10 ) give the same values ​​for the passive earth pressure coefficient . Use Ø' = 30° and 40°.