Practice Quiz

Civil Engineering PE

Category - Soil Mechanics

Start a Study Session Sign up for Question of the Day
What is the lateral pressure (in kips per square foot (ksf)) at the bottom of an 8-foot tall, 18-inch thick poured concrete retaining wall in an active pressure condition, given the backfill placed behind the wall is sandy gravel with a dry unit weight of 122 pounds per cubic foot (pcf), and an internal friction of 28 degrees? Assume the wall does not retain water and the Rankin active earth pressure coefficient Ka = 0.33.
  1. 0.32 ksf
  2. 3.2 ksf
  3. 322 ksf
  4. Not enough information provided
Explanation
Answer: A - The lateral force on an 8-foot tall, 18-inch thick poured concrete retaining wall in an active pressure condition with the given backfill is 0.32 ksf.
Solution: Use Rankine’s lateral pressure equation pa = ɣ h Ka
Where ɣ = 122 pcf
h = 8 feet
Ka = 0.33
pa = ɣ h Ka
 = (122 pcf) (8 ft) (0.33) = 322 pounds/square foot x (1 kip/1000 pounds)
= 0.32 ksf
Was this helpful? Upvote!
Login to contribute your own answer or details
Start a Study Session Sign up for Question of the Day

Top questions

Related questions

Most popular on PracticeQuiz