Earthquake!

Near Hercules, CA - 10:21:34 PST - 3.4

--
 Thanks,
    - Win

It was only 3.4, just a gentle shake here. I doubt anything got broke.

But it reminds me that I just spent a few hundred K for seismic upgrades on our new place, and it was probably a good idea.

John

Three *big* excavations in the dirt. Well, you jackhammer the floor out first. Fill them with much concrete, rebar, and 14" I-beams extending all the way to the roof; it's 3 stories. Rip off all the flooring and the roof and replace with structural plywood. Now start bolting and welding. Lots of inspectors get involved... concrete sample crush tests, pull tests on epoxied bolts, rebar inspection, plywood nail patterns, ultrasonics on all the welding.

This is pretty seriously downtown, and the entire front of the building is a major Muni bus stop, which makes it all a lot more interesting.

Wanna see pics?

John

Roll bars ?:-)

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
I love to cook with wine.      Sometimes I even put it in the food.

Sure!

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
I love to cook with wine.      Sometimes I even put it in the food.

But we like it here. You'd think, from a pure economic view, we'd be better off in Riverton, Wyoming or somewhere else where taxes are low and real estate is free. But the really good people don't want to live in Riverton, and people are our major asset.

Besides, owning a building five blocks from San Francisco City Hall isn't a bad investment in itself. This town is still just thinking about recovering from the dot-com bust, and commercial property is still fairly cheap... per square foot, maybe 1/4 the price of residential.

It's a seesaw: in 1998, anybody could find a job here but apartments were simply unavailable, and commercial real estate was outrageous. Now all those things are reversed.

Google Earth on 18 Otis, San Francisco. It used to be a fortune cookie factory.

John

A few years ago the Scientific American had an interesting article on Chinese temple construction - some of them have been standing for a long time and have survived a lot of earthquakes.

It turns out that the standard heavy tile roof is always mounted on a structure that allows the whole roof structure to jiggle from side to side or back and forth during the earthquake - the roof itself stays in one piece, and the supporting frames - wood sticks - distort without breaking.

Maybe your regulations were originally writtne in Chinesse or Japanese.

---------------- Bill Sloman, Nijmegen

Sounds like a very good investment. Pictures would be fascinating.

------------------ Bill Sloman, Nijmegen

Hello John,

Do you think everyone is ok? Didn't hear anything on local AM radio and nothing on the SF Chronicle web site yet.

Regards, Joerg

Not to mention the cascade of tiles you'd prefer not to stand under. In the '89 quake, the building next to ours was faced with brick, 7 stories high, and they all peeled off and fell on the sidewalk. It's a busy street and it's a miracle nobody was walking there; one brick would have killed you. I think 100% of the people who died in San Francisco were in masonry buildings.

John

Hello John,

Oh man, I am more and more surprised you didn't relocate to some less regulated place.

This all might make sense, some of it might not. When I see those 'earthquake measures' around here some of it is pathetic. Water heater straps that get fastened with teeny bolts that any serious wrestler could rip out of the stud in a second. A 5.0 could make the boiler do a tango because they are always full of water. Well, at least it'll be held by the gas pipe ...

Or the requirement to bolt to the foundation but anything on top is just wood sticks and nails. Then they allow heavy tile roofs above which is pretty much a guarantee that the house will pancake when the big one comes.

Regards, Joerg

Hello John,

But from "downtown" Riverton it's under 10 minutes to the airport. And a keyboard is still considered the thang whar the keys to the John Deere is kept. Nobody is going to complain when you crank the wood splitter all day long or the dogs run loose.

Where we live it's two minutes to the airport. Not that there's a whole lot of flight out of here but I can even jog to the FBO in under 10 minutes.

That sure sounds like a smart investment. Still I wouldn't want to live in S.F. or any other big city for that matter. Been there, done that, didn't like it. Life is too hectic there.

Regards, Joerg

Hello Bill,

I doubt it. What happens here is that many houses are originally built with wood shake roofs. Then the insurance company says they won't renew the contract unless the shake roof goes, too much fire danger. Some put composition on it which, for you Europeans, would look like glorified tar paper pieces with some finely crushed gravel sprinkled over it. That doesn't look too upscale for many people so they opt for tile. An engineer comes out, looks at whether or not the rafter construction can hold that or not and then blesses the plan or not.

AFAICT the dynamic properties of a house are not looked at during that assessment, just whether the trusses, rafters and load bearing walls are strong enough to carry the tile. Now you have house that is top heavier than it was before.

Regards, Joerg

Yes please. Pretty please!

--
 Thanks,
    - Win

Me too, but made a cute closing line.

We had the equivalent of that in England - a house that started off with a slate roof, replaced with ceramic tiles when the slates gave up the ghost as they do after 60 to 80 year - the nail holes enlarge until they are bigger than the nail heads.

The guy who surveyed the house did say that the roof beams were rathr mean ... but they weren't sagging.

---------- Bill Sloman, Nijmegen

Hello John,

That is indeed a miracle. Brick without reinforcement can be a problem. But I believe the old saying that wood frame or other framed construction is always better than brick and concrete is, to an extent, a myth. We had an earthquake in Germany and our house didn't even flinch. Despite a big heavy tile roof. Ok, I had to put a lot of stuff in the attic back into the shelves, it was a mess and the hutch in the living room suffered a big crack but nothing structural happened. One reason may be that there is rebar in all poured concrete ceilings and in the basement.

The frame construction of a nearby school gym didn't fare so well. IIRC it had to be closed until further notice.

Regards, Joerg

I posted a bunch to s.e.d. The building has poured concrete sides, and the front/back are "soft", mostly doors and glass, so the hazard is that it will parallelogram sideways, the sides will crumble and the floors will break away, pancake, and squash everything inside. It's

1935-vintage concrete, not prestressed and not nearly as tough as modern stuff. The plywood and steel and bolting are supposed to make this less likely. All our parts racks and partitions and stuff will be bolted to the walls, too.

Like our present place, it's mostly wood, RF-transparent, and in sight of Sutro Tower, 25 megawatts of involuntary EMI testing.

The worst earthquake in modern US history was on the New Madrid fault,

1803 I think, near what is now Kansas City and Memphis; it sheared off whole forests. Those cities take no earthquake precautions. Places like New York and Boston get occasional severe quakes and would be piles of rubble; fortunately the interval is 500 years or more.

John

[snip]

They hope. Sounds like the same kind of disaster planning that took down New Orleans.

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
I love to cook with wine.      Sometimes I even put it in the food.

No damage/people hurt I hope??

Are the pic's available yet? We have to do seismic bracing over here in New Zealand as it's a little shaky (more so further south; the capital has been flattened in relatively recent history). Our bracing of racks and other equipment at work is pretty solid stuff.

Cheers.

Ken