Wednesday, February 3, 2016

Geotechnical Engineering - A Tale of Two Torontos

This is a wonderful tale of geotechnical engineering in the marsh lands of Toronto, by the Humber River, site of slope failures and fish ladders.

This is life done right.  I applaud the geotechnical engineer.  Everywhere they are going with heavy equipment they have cloth and a foot or more of high-grade Granular A.  There will be no disturbance of the ground, and the stuff is easy to peel off at the end, with the fill being uncontaminated, and ready for re-use.  Great!  This is run by the City and is for a sewer relining project.

The other story, 500 m down the river, is not so happy.  Instead of the City, this is the local Toronto Conservation thingy group.  No pictures and vague names listed here, because what they are doing is almost criminal.  This is the site of my famous slope failures, where the river is cutting into the slope, on top of which are silly people with leaky swimming pools, causing the slope to fail.  These people have screamed enough that they are re-doing the protection wall.

You can imagine a shear block wall trying to hold this slope against the river.  The wall always looks perfect, but it is getting undermined, and the slope goes with it.  Some person got the low-ball contract to rebuild the wall.  I shudder to think what they are doing, since the wall is perfect, it's the channel at the base which is the problem.  I just would have just slung some armour stone in that channel.  Good enough technically, but maybe not the best 'political optics'.  The site is nearly impossible to get to, and there is a big river in the way, which is in flood right now with our weird winter.

No nice base for them.  They are plowing  through with heavy equipment, creating Flanders soup*, 2 to 3 feet deep.  They want to plant trees after, but the land cannot recover from this, because the silt gets sorted and packed.  Sort of like farm scrub land, but ten times worse.

I'm just watching the whole thing.  The rain and warm weather are all ready to conspire to cause a big slope failure, when they remove the old wall.  I can see houses and swimming pools coming down.  Big lawsuits coming.  But I never said anything, nor saw anything.  Stupidity is the best defence!  I'm sure everybody higher up is getting ready.  VW should write a manual!

*'In Flanders Fields the poppies grow...'  Because the land was so chewed up in WWI that nothing else can grow!

ps.  I want to push the fact that I never saw 'The World's Worst Geotechnical Project', the project is a work of fiction.  If some 'power' read this, and pulled the job from my imaginary yo-yo's then that maffie company would send someone to break my legs, or even worse, sue me!  :)  That's why this is a strictly satirical blog.

pps.  followups on my g+ geotechnical collection

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