Concrete foundation placed against shoring 2

[coloradobridges]

Four sided soldier pile shoring system installed to excavate for a bridge pier footing. Drilled shafts to be constructed, then concrete footing placed against shoring.

Any concerns about steel piles and timber lagging left in place next to the new concrete foundation? i.e. corrosion, rot, or other issues.

 

[SlideRuleEra]

As long as the reinforced concrete has adequate cover over its internal rebar, I would not expect any trouble. Have removed footings that were many decades old - the original forms had been left in place - no problems had appeared over that time.

http://www.SlideRuleEra.net

 

[born2drill]

Footings and foundation walls are frequently poured using the sheeting wall as a back form (an on-line system). This is especially the case for buildings that extend out very near to the property line (where there isn't enough room for a two sided form) and for footings inside small cofferdams.

Pile & lagging systems are almost always abandoned in place. Sometimes the top 3-5 feet or so of lagging is removed and the piles burned off, but that's about the extent of it. And if you pour your footing against the sheeting, it's not possible to remove the lagging. Will the lagging rot over time? Probably. Will it cause lateral movement of the soil and settlement? Probably not. Many contractors have dug up old lagging to find that it still has enough integrity to prevent the soil from filling that space.

 

[DRC1]

We usually use polyethelene as a bond breaker between the piles and lagging and the concrete. We have on occasion pulled the piles. If after you pour the footing, you are going to pour the walls against the soider piles, you will want to consider a waterproof membrane between the soldier piles and concrete. You will also need to use an external "A frame or design the soldier piles to take the looad of the form ties.
A lot has been written on lagging left in place. Generally old lagging is found in good shape years later in subsequent excavations. Lagging that has found to have rot is generally able to prevent movement of fine. Ie.,the lagging may lose strength, but it does lose significant volume that is displsced by the soil.

 

[DRC1]

Opps - I wanted to say " but it does NOT lose significant volume that is displaced by the soil"
Sorry.