earth pressure on retaining walls 2

[hemanthpds]

what are some real life examples of active and passive pressure conditions?

 

[PEinc]

Practically every retaining wall you see will have active or passive pressure acting on the wall. Active or at-rest pressures try to overturn and slide the wall. Passive pressure (or resistance) often prevents the wall from overturning or sliding. Passive pressure is not an applied force but rather is a reaction available to prevent wall movement. If available and sufficient, passive pressure (or resistance) only builds up enough to prevent movement. If insufficient or not available, the wall might move and fail.

http://www.PeirceEngineering.com

 

[oldestguy]

Fence post, mail box on a post, sheet piling no tied back.

 

[cvg]

active pressure caused this:

http://3.bp.blogspot.com/-0ZoBWle0b.../WvwMxlSYfew/s1600/tilting-retaining-wall.jpg

http://2.bp.blogspot.com/-gLms1_pAo...bdVQ/s1600/hudson+river+nyc+wall_collapse.jpg

1A.jpg

There was no passive resistance on these

 

[Doctormo]

First photo could be frost heave over the years or hydrostatic pressure also. Too much movement to be active earth pressure. Wall probably did not have much of a footing or reinforcing either.

Second photo may have been same as first photo, just 20X as large and rubble everywhere after it fell. I think that was in NY near NYC if I recall properly.

Active earth pressure - all cantilever walls not restrained at top and not ridiculously stiff.

Passive pressure - Soil behind guardrail post after it has been hit that was pushed up.

 

[bdbd]

When you trip on a stone while walking.

You fall because, active pressure (which is F=m*a acting on your body's mass centroid) causes more moment with respect to your feet's bottom, than passive moment caused by the stone. Imagine if stone was much larger, 1m tall, you will not fell over, because passive pressure is much more.

 

[HENRYZAU]

Gravity type retaining walls mainly rely on their weight to balance the active pressure; while embedded retaining walls e.g. Sheet pile wall rely on its bending action,passive pressure and strut/anchor (if any) to resist active pressure. The distribution of active and passive pressures can be very different in two different types of retaining walls.