🚀 go-pugleaf

Robb Briggs wrote:

> William Lynch <bozo.clown@big.top> wrote in message news:<3B75372C.D1B811C@big.top>...
> > > It is to laugh.  What school did you get your civil engineering degree at?
> > >
> > > Merritt
> >
> > I would have thought that that question should be directed to those
> > who built the central expressway in Kobe.  IIRC, that is the only
> > time where this design has been near the center of a major quake,
> > and the failure was 100%.
>
> As far as I know, Kobe was not considered a major seismic area, and
> therefore the structures were probably not designed accordingly.  If
> Kobe had the same seismic requirements as Tokyo does (or California
> for that matter), I'd bet that there would have been less damage.

The entirety of Japan is a major seismic area, and the Kobe-Osaka
area in particular has had some hum-dingers.  The Akashi Kaikyo
bridge, which was almost directly over the 1995 epicenter, was
designed to full seismic standards, and IIRC required no repairs.

>
>
> The double-decker freeways in San Francisco were designed in the
> 1950's.  At that time, they didn't use computers to analyze
> structures, and they didn't take into account the dynamic (as opposed
> to static) forces in earthquakes. And frankly, they didn't know nearly
> as much about earthquakes as they do now.
>
> -Robb Briggs, Civil Engineer.

I (not an engineer) was under the impression that the main reasons
for the catastrophic failures of the double decker sections were
twofold:  lack of flexibility in the joints, and lack of spiral rebar
to contain the vertical rebar.  These both obviously relate to the
knowledge level of the 50s, but is it possible to address these
problem areas and build a functional double decker structure?