expansion joint in foundation retianing wall
expansion joint in foundation retianing wall
(OP)
hi, I have a retaining wall which has a length of 70 meters. I have introduced expansion joints in the wall at 23 meters.
1 - Is it recommended to have the expansion joint also in the foundation knowing that there isnt any high watertable ?
2 - what is the purpose of putting a dowel bar inside 2 foundations separated by an expansion joint ?
Thank you
1 - Is it recommended to have the expansion joint also in the foundation knowing that there isnt any high watertable ?
2 - what is the purpose of putting a dowel bar inside 2 foundations separated by an expansion joint ?
Thank you






RE: expansion joint in foundation retianing wall
Mike McCann, PE, SE (WA)
RE: expansion joint in foundation retianing wall
RE: expansion joint in foundation retianing wall
Mike McCann, PE, SE (WA)
RE: expansion joint in foundation retianing wall
Regarding the dowels that generally are placed between 2 foundations, i can think of the rigid pavements. Which other places this kind of detail is placed ?
Thank you for the help
RE: expansion joint in foundation retianing wall
Mike, Would it not be better to say "To keep the footing segments aligned vertically, and to keep the wall faces in the same plane, yet still allow both to expand & contract longitudinally"?
What I often see are footings continuous under wall expansion joints.
The primary purpose of the expansion (& contraction) joints is to allow the visible portion of the wall to expand & contract without damage. The footing, being below grade, is not subjected to the same temperature variations as the wall and is less likely to experience the same magnitude of thermal movement.
Ralph
Structures Consulting
Northeast USA
RE: expansion joint in foundation retianing wall
Thank you
RE: expansion joint in foundation retianing wall
Mike McCann, PE, SE (WA)
RE: expansion joint in foundation retianing wall
geo321 - Greased dowels are indeed common for pavement. Dowels sleeved or wrapped to prevent bond at one end are more commonly called for in building & landscape situations. Same principle, different method.
Ralph
Structures Consulting
Northeast USA
RE: expansion joint in foundation retianing wall
RE: expansion joint in foundation retianing wall
No joints needed in foundations.
RE: expansion joint in foundation retianing wall
RE: expansion joint in foundation retianing wall
RE: expansion joint in foundation retianing wall
another couple of questions
1 - Walls expansion joint will be filled with a joint filler and sealant. Is a water stop needed along the joint ?
2 - At contraction joints, horizontal reinforcement will be stopped and a sleeved dowel bar will be located. Is this the common practice ?
thanks again
RE: expansion joint in foundation retianing wall
For retaining walls, we would drain the backfill using either 1) a continuous drain tile or 2) weep holes at regular intervals. We would only provide waterstops if we felt it was an appearance problem or it was necessary because it was inside a building basement. Weep holes can sometimes be a safety concern, if it can drain onto a pavement that can then create ice.
RE: expansion joint in foundation retianing wall
Since the wall is reinforced from both sides (vertical steel to take into account the bending stresses and horizontal for shrinkage/temperature stresses), and expansion joint is introduced every 23 or 30 meters , I believe that the crack which will be developed will be minor and most likely not visible.
I understand that u introduce a contraction joint in a slab on grade or a rigid pavement since these can be unreinforced elements so u need to dissipate the thermal stresses but for a retaining wall reinforced from both sides and separated by expansion joints, I cant figure it out !
RE: expansion joint in foundation retianing wall
RE: expansion joint in foundation retianing wall
Based on my experience and perception, contraction joints will be effective only if they are located such that they coincide with reduced horizontal reinforcing. Typically every other horizontal bar is cut at the contraction joint.
Ralph
Structures Consulting
Northeast USA