movement joints in retaining walls

[engstructural]

Can anyone advise me of sensible length of retaining wall between movement joints:

A: for reinforced masonry walls with concrete cavity fill.
B: Reinforced concrete shuttered walls.

Also would this differ if these walls were used in basements or semi-basements assuming the wall was tanked externally.

Thanks for any help.

 

[civilperson]

Architectually exposed, use 24' maximum. No need if not visible such as buried or covered.

 

[LobstaEata]

Hi eng

I've always used the rule of thumb of 30 ft for contraction joints and 60 ft for expansion joints. Reinforcement should always be carried through joints to maintain relative position of the wall.

Hope this is helpful.

PE in New England

 

[engstructural]

Lobstaeata,
If you carry the reinforcement through the expansion joints would there not be a durability issue? also I assume this would not apply to basements to ensure water-tightness?

 

[hokie66]

You will get different opinions on what reinforcement, if any, should go across a wall joint. My company normally specifies galvanized dowels, with a slip cap one end.

Basement waterproofing has to include a flexible sheet across the joint.

 

[LobstaEata]

Eng

Reinforcement through contraction joints present no durability issues whatsoever, since contraction joints a primarily for controlling the location of cracks due to concrete shrinkage.

Reinforcement through expansion joints however should be able to slip on one side of the joint. Different techniques have been used throughout the years such as wrapping dowels traversing the joint with building paper, greasing a smooth dowel (galv the dowels is good here), or using a slip cap as mentioned by hokie.

Watertighness is another question altogether. If it is imperative to ensure watertightness for the enclosure, then neoprene waterstops have been very effective over the years. If it's a large residential beasement, then less expensive measures could be employed, such as applying myrradrain on the outside face of wall directing runnoff water to the perimeter drain in conjunction with installing a flexible polyeurethane seal at the joint.

PE in NE

 

[civilperson]

PE in NE, I assumed you resided in Nebraska, (NE). New England is not a state that most recognize.

 

[LobstaEata]

Eng

Some of us seem to think New England is a state unto itself. I'm a Mainer and am far too used to our little corner of the world. NE is a common term around here for New England, so my apologies for stepping on any Nebraskan toes.

PE in the great state of New England ;o)