AISC Webinars

For anyone interested in learning a lot in a short time, I couldn't recommend anything better than the AISC steel webinars. Kick ass engineering. It is a great format - recorded lectures by industry experts especially meant for a young engineering audience. There are 4 available and each is 6 hours long.

Screenshot from AISC Webinar

There are a few interesting things you should know about these. First, these were originally just normal seminars that the experts presented around the country. There was no intention of webcasting them. However, people rated them so highly that a clever person at AISC decided that people could really benefit from them. And so the experts came back for an encore presentation that was recorded. That means they had plenty of practice and time to work out all the bugs. The final result is quite good, and well worth your time. I've seen all them thru, some more than once. Don't plan on doing them all in one week, your head will explode.

MSC is another great resource freely available to AISC members

When you're done watching, try to explore some of the other resources that AISC makes freely available to all its members. There is the Modern Steel magazine, Boxed Lunches, the Engineering Journal (and archives), the FAQ's, and the "Ask AISC" where you can actually pose a question to the steel experts there. That last part is generally a good resource, but you get what you pay for sometimes. There really is no other construction design organization as well organized and offering you more opportunities to learn than AISC, and you should be taking advantage of it. Well, maybe ASCE but I haven't seen them post any free webinars - hint hint.

Further Earthquake Links

For those who have more than a passing interest in Earthquake research happening in the Eastern US (i.e. not California) we have plenty of resources.

First off is the USGS - US Geological Survey. They are the clearinghouse for all things dealing with rock, soil, faults, etc. You will still need a qualified soils engineer to determine site classification, but their soil explorer program can sometimes provide you with some interesting advance information. If a previous soil boring was reported to the USGS, and it showed bedrock at 5 feet, you can make an assumption that soil classification will be favorable.


Next up is the Mid-America Earthquake Center. This is a group of researchers dedicated to mitigating the possible problems that a large earthquake in the Central US might cause. They especially focus on the many historic buildings (unreinforced masonry) and even modern buildings that were built before awareness of the seismic risk in the area. The worst historic earthquake (magnitude, not damage) was in this area, so there is a good reason to be concerned. A good source for graduate funding, too.

Then there is the Central US Earthquake Consortium. This was started by FEMA to handle the human aspects of Earthquakes. So this doesn't deal so much with research, but is all about the government response and disaster preparedness/awareness. It's all about coordination. A good resource nonetheless.


CERI is another great resource. They have a lot of independent information, as well as links for teachers and students. Was able to find a waveform taken from a Missouri station of the earthquake here. These people also have graduate funding programs available for students.

More general information about midwest earthquake risks:
New Madrid Seismic Zone
Wabash Valley Seismic Zone

I believe the most important thing when anyone asks an engineer about these topics, or related disaster topics such as building collapses, hurricanes, etc. is to refer them to the appropriate spokespersons for our industry. Alternatively, read up or interview someone from one the groups in advance if you know that a newspaper or media outlet will be contacting you for a response. It is essential that the public knows the most recent information and that we present the consensus opinion to the media. Don't take the fools way out and use the publicity to invent your own conspiracy theory.

update - 5/30/08

How could I forget about NEHRP? The National Earthquake Hazards Reduction Program is another government entity dedicated to reducing earthquake losses in the US. This is a great resource for any structural engineer dealing with seismic design. It is especially relevant for older buildings that are being updated or going through seismic hazard mitigation. The methodologies used are somewhat different from the IBC and UBC code provisions for new buildings and you won't always get a "yes/no" answer on a design. They have also posted a recent newsletter describing the efforts to develop a consensus based document for performance based design of seismic resistant structures. See the interim FEMA 461 document here.

Midwest Earthquake

Everyone by now has probably already heard of the earthquake that took place on Friday. See USGS data for information on our little friend. It was centered about 150 miles away from Indianapolis, but still quite powerful when it arrived. The attached map from USGS shows the event intensity and peak ground motion.

This earthquake did a lot of good things from my perspective, and didn't really cause any harm to properties or people. Those are the kind of earthquakes that save lives, in my opinion.

First, it brings earthquake and emergency preparedness back to the forefront of media attention, and that is always good. Next, it reminds building owners that they have an obligation to build and maintain safe structures. But most importantly (from my point of view), harmless earthquakes give structural engineers a great opportunity.

I think going through an earthquake can give just about any engineer a better understanding of how the ground moves. Looking at seismic data for historic events, it just doesn't affect you the same way as experiencing an actual event. What I learned was this - the ground (and building by extension) does indeed move. I can imagine that a bad earthquake would be truly terrifying. I also learned that earthquakes make noise. It was a low rumbling noise, not loud at all. I also learned that nothing I had experienced in my life so far resembled what happened, but I have to say the Modified Mercalli Intensity measurements are pretty accurate if you need a comparison. See Wikipedia Intensity article for a good explanation.

Now for a little science lesson... Earthquake magnitude is measured by the "Richter Scale" typically. This represents the energy released during an event, and is related to the waveform of movement radiating from the epicenter. It is a mathematical measurement, and completely free from objective interference by people. A 5.2 magnitude earthquake somewhere else in the world releases the same amount of energy as the one in Illinois did. One note about the Richter scale is that is a logarithmic measurement. Thus, a 6.2 EQ would indicate of release of 32 times more energy than the 5.2, while a 7.2 EQ would be 1000 times more energy. In other words, if you thought the 5.2 was scary you ain't seen nothing yet. See Wikipedia Richter Scale article for more info.

Now, the effect of the earthquake has a lot to do with the specific area it occurs in. Here in the midwest, we have a wonderful rock layer that transfers and amplifies the waveform quite easily. So it's not surprising that people all over the Eastern US felt this. The Modified Mercalli intensity scale includes the actions of the soil and rock, so it's more useful for discussion when talking about structural engineering. We experienced a III-IV level intensity here in Indianapolis. Which is pretty amazing considering how far away the epicenter was. If a large earthquake were to hit the New Madrid fault in Northeast Arkansas, like many geologists say could happen, it is likely that many places in the Eastern US will be affected. It may not happen for 2500 years, it may happen tomorrow.

Back to the post at hand - This EQ gives structural engineers an opportunity to discuss seismic events with clients, business owners, and the public. It is essential that they understand the real dangers of earthquakes in the Midwest. We should not misrepresent the danger or try to scare people, but do let them know that they have choices when it comes to EQ design. Any building can be made more robust. Masonry parapets can be secured against toppling, gas and water pipelines can installed with flexible connections, and hospitals and important bridges can be designed such that only an atomic bomb will close them down. It's a lot of work, it's expensive, and construction proceeds slowly. However, they say the best time to patch a roof is when the sun is shining.

Structural Engineering Weblog Manifesto

This weblog was started because structural engineers were not taking advantage of the opportunity to communicate with each other. While there are any number of architectural blogs, even sites that rank them by popularity, there are no blogs concerning structural engineering. Therefore, this blog is committed to the structural engineering community and to everyone who is interested in structural engineering.

This website is inspired by the idea that people want to know how buildings are constructed and why they don't fall down in a strong wind or earthquake. My hope is that anyone can visit the site and connect to the topics in some way. However, I'll probably put a lot of industry-specific information here so let me know if any of it is unclear and I'll repost with clarifications if possible.

Everything you read in this blog will be filtered through my eyes. So, let's talk about me for a bit. I'm a structural engineer working in Indianapolis. I got my BS from CMU and my MS from TAMU, and I have a PE in Indiana. I work on many types of buildings and structures - industrial, commercial, and residential. I try to stay involved with the engineering community, so drop me a line if anything catches your eye and you want to share it. I'm also very interested in everything my architect friends have to say, so you will probably see a lot of that. I also enjoy discussing technology not related to construction.

Structural engineering is a subtle art and a great structural engineer is sometimes hard to recognize. Unfortunately, this has led many people, politicians, and architects to suspect that engineers are merely technicians, putting numbers into arcane mathematical formulas and then rounding up an order of magnitude just to be safe. Rest assured that there are great engineering firms out there, and great structural engineering is anything but a lost art.

This site doesn't believe that one-size fits all or that pounding a square peg through a round hole is an economical solution. This blog aims to separate great engineering from the mundane, and we welcome all comments and advice. If you know of any great projects or want to share a special topic with the rest of the world, feel free to leave a note for us and we'll check it out. Thanks and welcome to our place!

Test Blog

This is a test of my blogging system. Foo.