Existing Timber Crib Walls
Existing Timber Crib Walls
(OP)
I am working on a very complex wall design to replace an existing tiered timber crib wall system. The bottom wall has deteriorated. The upper wall looks as if it was recently replaced by the neighboring property owner. There is limited room to work. The upper wall retains a parking lot and is 22' above the bottom of the lower wall with a horizontal length of 15'. Town is after lower wall owner to replace wall (my client).
Wall is too high to install gravity wall system, (Recon or Redi-Rock) unless tie walls are left in place.
Here's the question can the existing cribbing be left in place? If so what steps can be taken to preventdeterioration and eventual voids behind the wall.
This is a cry for HELP!
Joe
Wall is too high to install gravity wall system, (Recon or Redi-Rock) unless tie walls are left in place.
Here's the question can the existing cribbing be left in place? If so what steps can be taken to preventdeterioration and eventual voids behind the wall.
This is a cry for HELP!
Joe





RE: Existing Timber Crib Walls
Or, could you soil nail and shotcrete the lower crib wall after attaching a drainage geo-composite to the front of the crib?
RE: Existing Timber Crib Walls
From your response, I'm assuming you have experience with leaving the ties in place.
Any other info would be great, since i need to "sell" it to the code official.
Thanks again!
Joe
RE: Existing Timber Crib Walls
I wouldn't worry too much about the deterioration of the timber ties, it's not as though the timber is going to vanish, and the exposed timbers may be significantly worse than those buried in the fill. You can probably reduce the deterioration by providing proper drainage to the structure.
RE: Existing Timber Crib Walls
As I already mentioned, you could soil nail the wall but you would need a specialty contractor to drill, nail, grout, and shotcrete. However, any dummy can drive or drill in soldier beams, nail on geocomposite drains, stack precast concrete or pressure treated timber lagging, and backfill between the lagging and the old wall. If the job is small, you may not find someone who is interested in doing the soil nail option.
RE: Existing Timber Crib Walls
RE: Existing Timber Crib Walls
MSEman - The is actually in northern New Jersey.
There is approximately 5' of clearance from the existing building to the lower wall and the lower wall is approximately 8'high. The upper crib wall is approx 12' high and starts 5' feet behind it.
Also, since this system is in an urban area, the fill is loaded with misc debris.
Just another day in the office!
Joe
RE: Existing Timber Crib Walls
With only 5' of room to work in, you also would have problems installing soil nails. It may be possible to build a gravity block wall with minimum embedment below OG. However, you would need large blocks without geogrids and you may have to design for large sliding and overturning forces from the upper tier wall(s). You might have to excavate by hand and you may need to set the blocks using a crane sitting behind the top of the upper wall if you can't reach from the ends of the building. Good luck with that one.
RE: Existing Timber Crib Walls