Wednesday, March 25, 2009

Niagara Tunnel: Doing It Right - Part 1

This is an academic exercise for those interested in rock mechanics. There is no news here for political scandal-mongers, since the project would have been canceled, had somebody insisted on doing it right. As it was, they could easily find someone to take the money and run.

The cheapest way to do a tunnel is to take a used tunnel boring machine (TBM), and run it through unsupported. You can do that in limestone. Anybody pulling out a core of Queenston Shale, and looking at it for 2 minutes would quickly see that it resembles limestone, it is a really good rock! Just ignore it after it's been in the core box for a few days!

Everybody gives lip service to the high horizontal stresses in Ontario, but nobody knows it lies in bands, associated with the megathrusts I have written about. That means the distribution is uneven, which could mean there are zones with higher stresses that we have ever encountered before. This is something to look out for.

For 30 years, I was always worried that the rock stresses underneath the St. David's Gorge could be horrendous. What would be the consequences? What would it look like? Is this something for Science? Sadly, we will never know, because they are doing diddly-squat for science here, they are just trying to wallpaper their bo-bo's.

So let's start our fantasy. We need to transfer a decent amount of water, not the piddly trickle allowed by the 1909 treaty, but something that is cost effective.

I'm in charge. Mel has been beaten back because it is a new age of enlightenment, and he has screwed up too many times. Since this is a fantasy, I have not crumpled up into a ball, but I relish the challenge. I am still terrified of the rock, since I have had many years of experience in this stuff, and, being Canadian, I expect the worst.

As I have always done, I would open-source the science on this, and try to find people who are brighter than me. I want to know how bad this rock really is, so I would try something innovative with the core drilling. I would pull core and wire it up immediately for measurement and sonics. I might try to throw in a horizontal hole. Most likely I would just assume the worst.

(to be continued)

2 comments:

Harbles said...

I found this on the Google.

The section on the Upper Rouge Tunnel project (pg 302 - 310 or so) sounds like similar conditions to Becky. They have chosen Finger shields and a double pass concrete liner system rather than the shotcrete approch. Care to comment?

Harold Asmis said...

I'll incorporate it into my fantasy.