Geo: Force on Wall w/ Wall Friction

[GTScott]

Wall Height = 10'-0"

Well-graded granularl backfill, internal friction angle = 32 degrees

Unit weight = 115 pcf

Wall friction angle = 16 degrees

No hydrostatic pressure behind wall...just the fill

Find the lateral force against the back of the wall.

A) 1600 lbs / lin. foot

B) 1750 ""

C) 2750 ""

D) 18750 ""

-GT

 

[3gorgesdam]

Quickly go to ka table get a number that is for alpha=30 and friction angle =15, I came up with 1990 lbs for force. Knowing ka should be a bit smaller for the exact condition, 1750lb is my choice. In this situation, no need to be exact.

 

[EL Nica PE]

(0.301*115*100)/2=1765

 

[GTScott]

(0.301*115*100)/2=1765

Same thing I did. Do you have to take into account wall friction?

 

[EL Nica PE]

No. This is just a matter of force pushing on wall.