jill's blog

Data collection, storage and retrieval are vital functions of any modern business, large or small. In the United States, 99% of roughly 29.6 million businesses are small firms (fewer than 500 employees). We would expect that most of the country’s 18,000 large corporations to have hardened data facilities with bullet-proof business continuity plans – and given the high level of reliance on data integrity, that small businesses would follow suit. But that’s not necessarily the case. For example, Symantec recently published the

The Open Hazards Group accurately predicted the damaging earthquake that struck Taiwan Saturday evening at 9:02 pm. A screen shot of the forecast shows the openhazards.com forecast details. The contour plot shows earthquake probability and the blue marker depicts the epicenter of the actual quake.  The forecast was posted to our website before the earthquake occurred.  An aftershock forecast will be available on our website after midnight California time when our site updates worldwide forecasting.

Here's our first update on the December 19, 2009 Taiwan earthquake: OpenHazards Group, Inc. has translated reports from the China Times, which features excerpts from other Chinese newspapers.

What do most modern motorcycles, cars, highway signs, some tall buildings, domed arenas and modernist style industrial and commercial buildings have in common? The space frame: a lightweight, rigid frame made of interlocking bars or rods (struts). Arranged in a geometric pattern, the struts in a space frame building provide stability, strength and resistance to rotation or movement due to external forces such as strong wind or ground motion.

An unreinforced masonry (URM) bearing wall is a URM wall that provides vertical support for the floor or roof of a structure. URM buildings are not strengthened (reinforced) with embedded steel bars, which makes them extremely hazardous in seismically active regions. Materials used in these kinds of buildings are generally unreinforced adobe, clay, concrete or concrete block, brick, or rubble. These buildings are popular all over the world, even though they tend to collapse in strong earthquakes.

A bearing shear wall is another term used by structural engineers and builders to describe a type of wall, or actually a wall system designed to provide strength to a building by transferring stress to the foundation.

This blog is a continuing discussion about building types, and how they respond to earthquakes. Today’s blog is about tilt up buildings. (Once all the most common building types are explained, I’ll move on to translating peak ground acceleration and “g” forces, and the term probability.)

What’s a tilt up?

What type of building do you live in? work in? play in? If your children are in school or college, what kind of building types do they take classes, or live in? Occupied with the business of living, you probably don’t think much about the strength or safety of the walls that surround you or the roof overhead. But knowing a little more about the structures you spend your time in could benefit you in all kinds of ways – and maybe even save your life. Let's start with "wood-frame" construction.

I grew up in earthquake country – otherwise known as the Los Angeles greater metropolitan region – and lived through dozens of “felt” earthquakes. Before the magnitude 6.7 Sylmar (San Fernando, CA) earthquake of 1971, I thought earthquakes were kind of fun. Of course, I was still a teenager, and thought I was invincible. A little “jiggle” now and then made life a little spicier, and no real damage occurred from the mild, infrequent events spanning most of the 1940s, 1950s, and 1960s.