Submerged Untreated Timber Piles Biodegradation

[connect2]

So.....

Submerged Untreated Timber Piles doing a condition assessment of. Biodegredation, biodeterioration, bacterial wood degradation would seem to be a relatively new, 10 or so years, condition coming out of Holland and based on a large scale assessment of submerged untreated timber piles under many many of their buildings. The cellulose structure of the sap wood deteriorates, for a number of reasons, despite the pile being submerged, articles also show up in the mag Structure June 2007, and especially Dec 2013. Typically the opinion has been that as long as the pile is submerged it can't deteriorate. Say it ain't so Joe.

Question is, is anybody familiar with this? Has anybody done any testing for it? Can any body name some labs that are capable of identifying/quantifying it?

 

[precast78]

I am not familiar with it but how about the part of pile that is exposed to changing of water level?

 

[cvg]

and that part of the wood which is home to marine borers?

 

[CELinOttawa]

Yup... In mud, after a depth that varies principally by climate, the wood won't rot... Above that depth it can be eaten both at the macro and micro level.

Cyclical wetting is the worst possible exposure, with stable dry being okay and stable wet being "good". None of those are perfect... Perfect non-rotting comes from submerged and uneaten.

Interestingly I was present for removal of the original timber piles from the Lisgar Street bridge here in Ottawa... Approx 120 years and they looked like they could be purchased at Home Depot. That was fully submerged and mud encased.

 

[BigH]

I am aware of wood piles that were exposed years after installation for a quality check and they were in excellent condition - however, after backfilling, then next year, they were unearthed again and had shown deterioration - likely due to the wet-dry cycle - which is bad news. Parliament buildings in Sweden, if I remember the article correctly, are on piles installed in the 900s - and I doubt that they had any engineering protection.

 

[msquared48]

I have run into two situations:

1. Treated Piling with degredatoion from rot and marine borers at the water fluctuation area, and extending up snd down from there, and

2. A 24" diameter DF pile from the turn of the century that was as good as the day it was put in, and below the water table. We used it as one of our pile to replace a one steel pipe pile after the condition and capacity were verified. That pile appeared to be untreated.

Mike McCann, PE, SE (WA)

 

[BUGGAR]

We pulled some timber piles from a pier constructed in 1913 in San Diego Bay. They were perfect below the mudline. It was impressive to see the quality of the timber they used. The good trees are all gone now.

ps: We went to the San Diego Historical Society and got original photogaphs taken during the construction of this pier. Priceless!