On 5 Oct 2004 22:09:58 -0700, (Raymond
Yeung) wrote:

My wife and I are looking for a house/condo/apartment in the
South Bay Area of California. We've some earthquake related
questions:

1. There's a 8-storage metropolitan apartment building that the
builder claims to be built with post-tension construction. It
was built in early 2003. Is this technique something especially
for earthquake? Or is it typical of any building these days,
regardless of geographical locations.

The most dangerous buildings are unreinforced masonry; this
building would be reinforced if post-tensioned.

Remember though, the goal of seismic structural design is not to
save the building; it is to save lives. Even a well-designed
building could be a total loss after an earthquake. This is an
important consideration if buying a place, since earthquake
insurance in California is fraught with difficulties.

2. Given the current construction methods, what's the safety profile
of such a multi-level building versus the usual 2-3 story houses?

A two/three story house would normally be made of wood, the
safest form of construction, provided shear walls have been
installed and the structure bolted to the foundation. It is
important that you check for this. Bewae of weak stories, such as
a typical SF house with garage below and living space above.

Interestingly, Loma Prieta didn't even knock down the shampoo
bottle I kept precariously on the top of the shower stall; we
lived in a two-story Daly City house, on of Malvina Reynolds'
notorious little boxes all made out of ticky-tacky.

3. There're a lot of 40-50 year old houses selling at over half a
million here due to school district. My impression is that wood
framed structure tends to age and become weaker. Is this true?

Actually, wood structures tend to flex in an earthquake instead
of breaking. They make a hell of noise in even a small quake,
though. Again, though, keep in mind the goal is personal safety,
the house be damned.

Given the insurance problems and the published earthquake
probabilities, I wouldn't want to own a house in the shakey parts
of California just now.

See http://quake.abag.ca.gov/ for some very good info, especially
shaking maps and liquefaction maps.

************* DAVE HATUNEN ) *************
* Tucson Arizona, out where the cacti grow *
* My typos & mispellings are intentional copyright traps *