Monthly Archives: March 2010

Thea Render – Depth of Field

I just bought the beta version of Thea Render, a software package that should help me get better at producing photo-realistic bridge models. I am hoping to produce photo models part-time for bridge design firms.

A) I like drafting/rendering/imaging, B) I know something about bridges and C) I could use the money! I thought videos would help me remember all the different steps and since youtube will store it for free…..I thought why not.

So here is a first/quick video showing depth of field in Thea.

Rapid bridge construction

Update: Mark (comment) is right that headed bars are gaining more interest in the bridge community. Here is a paper by John Stanton on rapid construction details.

Sitting in a seminar for rapid bridge construction in seismic regions, by John Stanton. (uw)

He is explaining an ABC cap/beam connection and a rapid pier design. The main point, typical of precast construction, is the lack of good connection details.
Mr. Stanton is discussing how they used 6-#18 bars to connect the pier cap to the columns. The development length was tested in the lab because the cap depth did not provide the code required development length.

He is discussing how this connection works well under sesmic loading.

Sent from iPhone

Winner chosen – St. Patrick Island Bridge – Calgary

The Happy Pontist pointed out that a winner was chosen for the St. Patrick Island Bridge.

In what can olny be called sour grapes on my part, I think the finally solution was a letdown. Two arches connected by a little platform bridge, meh, okay but nothing special.

I can’t belive this solution was the stated goal of the competition? Does it really compete with Calatrava’s design? I don’t think so. This is a bridge chosen by politicians. Okay, but safe.

We have a few of these kind of arches in our state, (we should join two bridges together!) maybe I could just send them the calculations and save them some more money….again sour grapes, but really, that’s the best solution?

Sourgrapes recreation of winning design.

Monday – yuck

Okay some Mondays are tougher than others but we have to soldier on….

Today I started teaching the moment distribution method started by Hardy Cross. (who is a minor god by the way.) We skipped the slope deflection method (not sure why) and then on to the direct stiffness method.

I have been busy with a) real work b) teaching and 3) thinking about a new part-time, side job. I keep thinking there is a market for 3D renderings done by a real bridge engineer. So I have been looking around at photorealistic software.

The problem is, I’m cheap! An intro package goes for $250 dollars and the big players are around $1500. So my question is, would design firms like 3D rendering done by a professional bridge engineer?

Women Bridge Engineers

I was looking around the web for women (wow does that sound wrong!, keep reading..) bridge engineers. I know about Linda Figg and the contributions of Emily Roebling in getting the Brooklyn bridge built but I have not heard of many high profile women bridge engineers.

According to an article in the Washington post about “17 percent of undergraduate engineering degrees were awarded to women in the 2006-07 school year, the latest for which information is available, according to the National Center for Education Statistics.” They went on to say “the low numbers of women are holding the field back.”

I would say that the 17 percent reflects the number of women in my engineering class. So the first barrier to women in engineering is based purely on numbers. (In structural engineering I would wager the numbers do not reach 10 percent.)

I am not smart enough to understand why this imbalance in engineering is occurring, but with two daughters I am concerned with the trend. What do you think? Are things improving for women in engineering?

from sliderulemuseum.com

Some links:

Direct stiffness method

I have to teach the Direct stiffness method in a couple of weeks. Could someone point me to a nice basic introduction textbook or paper that I can use for my class?

The hardest part of teaching is breaking down information into easy step by step pieces…..and I am struggling a little bit with how to approach this subject. (It is not easy to teach to a large class something as troublesome as this type of analysis…)

I would also like to develop a spreadsheet or mathcad sheet to help out with problems. If you have something like that I would appreciate some help!.

Thanks!