SAZABI

原帖由 MyOMy 於 2008-5-15 13:42 發表
Oh, for Ditchmond. If you are scarce of earthquake, don't live there. Anywhere in Ditchmond you dig 3 feet you find water. Some people using the term "vaporize" to visualize the after earthquake effect.

hee... not sure about other stuffs you said, but this is techincally incorrect.

SAZABI

Dear MyOMy,

1. The ground water table surely has sth to do with liquefaction (yes, you used the right term for that effect under earthquake).  However, the main thing would be the soil condition encountered on site.  For example, if you get a till-like material in the ground with water table just 0.5 m below the ground surface, I don't think you will get liquefaction under this case.  There are lots of places in greater vancouver with shallow water table, not only richmond.

2. Of course no government will deny the possibility.  I wouldn't say that the risk is minimal.  Even the site just next to the new skating ring (currently under construction) will have liquefaction problem under the right earthquake (yes, liquefaction doesn't not occur in every earthquake, it depends on the magnitude as well).  However, this problem can be treated if you know the site condition before hand.  If you pay enough attention, you should see a lot of sites being pre-loaded, or doing vibro compaction in Richmond prior to actual construction.

3. Even if liquefaction occurs for certain area in Richmond (not the whole richmond will undergo liquefaction).  It doesn't mean that the land will not be suitable anything in the future.  Pore pressure will eventually disapate and people can always do sth after.

4. Richmond being flooded to a point where the land disappear is always a stupid idea imo.  Don't want to go into details on this one.

Hope that gives you more info on this matter.

SAZABI

yeah... i just want to clarify some 'myth' that the general public has some mis-interpretation on earthquake.  I mean, if the earthquake gets up to 8.0, a lot of us will die anyways whether we live in vancouver or richmond lol.  So if earthquake is a 'big' concern, don't live in greater vancouver

SAZABI

原帖由 shutterbug 於 2008-5-16 13:14 發表

I think the difference is that if Rmd does liquify and wipes out then the chances of dying there is extremely high compared to Vancouver where the chance for survival is much higher at least...

hmm... can you explain why liquefaction yields a lower chance of survival please?

SAZABI

原帖由 shutterbug 於 2008-5-16 16:04 發表

that's just my perception...nothing scientific or statistic...

My understanding of "liquify" means that there's no more land or the land sunk or something. So if one doesn't even have a place to res ...

err... that's not what really liquefaction means...
anyways, don't worry about it, it is not as bad as the general public thinks.  (it is still a bad thing tho)

SAZABI

原帖由 shutterbug 於 2008-5-21 11:00 發表

http://gsc.nrcan.gc.ca/urbgeo/geomapvan/geomap8_e.php

OK, I read some more...so it's not as dramatic as I thought, which is like in movies...LOL

But still I think the damage will be much worse in t ...

hee... i click on the link and "WOW!!"  B/c I see this map every freaking day in the office lol (the one we got has more infomation, even the geology of the area, but the main components are the same)  Don't worry la, even the map highlight the whole area as red... again... not all the area will undergo liquefaction neh.

As for damage, I would think... okie... I should not discuss these thing in public b/c i don't want to be liable.  Hmm... all in all, earthquake engineering is a complex problem neh.  To assess "damage", u have to look at liquefaction and also the ground response and the period of the structure.

As for airport, I can pretty much gaurantee u that it will not undergo liquefaction.  Engineer can make that problem go away easy.  Just that it needs money.  So usually heavy civil structure will take that into consideration.  For example, the Pitt River Bridge that is building now has been "treated" to take away the liquefaction problem.

SAZABI

原帖由 utopia 於 2008-5-21 14:51 發表

As for my boy, he is carrying double degree, working on his CSC, plus he is thinking to get another minor. He wants to make sure he has enough education before we move to the states.

Just a little suggestion.  If he is willing to spend that amount of time in education, it is better to get a master or PhD degree.