So yesterday I tried to get sustainability into company policy. A coworker suggested I should be fired for trying. Exciting being an engineer.
I haven’t written much lately for a number of reasons. For one, it is difficult to say anything new and meaningful.
Write about sustainability, check, bridges blow up good videos, check, sketchup, check, teaching stuff, check, change anybody’s mind…..well maybe not. Keep trying, check.
Other reasons – trying to finish teaching this semester, writing a children’s book and getting back into traditional painting.
BUT, I did get one highlight concerning my book. It’s a basic set of problems book but it is useful. The funny thing if you catch the sales rank at exactly the right moment, you can be in the top ten and then when you check later you fall out if the rankings.
For now, I have written a top ten book! Yea!
This is a powerpoint presentation that I put together for a class on sustainability. It gives a quick overview of three infrastructure rating systems in the US, Envision, Invest and I-Last.
Not my best video, I kept looking at the clock….oh well, hopefully something in it is useful. (Plus I had the worst case of marble mouth.)
For ipad users, click here for a better quality video.
Pretty big truss to slide in, I would imagine a lot of math was involved.
Coffee Break GroveBot, used on construction sites.
The white part of the building is the precast cladding on the Scotia Center in Calgary. My father manufactured all the precast for the building and I remember washing the concrete before shipping it to the site.
Scotia Center finished in 1976 at a cost of $30 million dollars.
So time for some shameless promotion for my wife, Kori.
Like a lot of engineers, sitting all the time, I gained a little unwanted weight. Plus, as an older guy I started losing muscle tone. (Lifting a pencil does not build the biceps!)
So my super fit wife, a microbiologist by training, and a BeachBody coach jump started me back into fitness. Right now I am lifting weights with her and the BodyBeast AND doing Insanity workouts.
Kori is a certified trainer in Insanity, P90X and Turbo kick!
Right now I go to her Insanity classes and collapse, but in a good way. I have to say lifting weights and having a trainer help you get in shape is amazing.
Anyway, if you live in the United States or Canada, want some help getting in shape or want some guidance on tools to get in shape, contact Kori here:
Contact Kori – BeachBody Coach
Contact Kori – BeachBody Coach
So you want to be an engineer, can you pass the test?
David sent some great links on the Gladesville bridge in Australia.
Gladesville Bridge: The span of the bridge is 300 m (1,000 ft) and at its highest point gives a clearance of 60 m (200 ft)
Gladesville Bridge is an arch bridge that spans the Parramatta River, west of central Sydney, Australia. It is a few kilometres upstream of the more famous Sydney Harbour Bridge. At the time of its completion in 1964, Gladesville Bridge was the longest single span concrete arch ever constructed. Gladesville Bridge is the largest of a complex of three bridges, including Fig Tree Bridge and Tarban Creek Bridge, designed to carry a never built northern expressway.
Here is a film of the construction, it is amazing how far (or not) building techniques have advanced.
And check out all the safety rules that are broken, people riding in precast, no hardhats and no safety lines. My favorite is the guy with the red sweater casually wrapped around his shoulder walking on top of the arch. (Time 14:09)
Most engineers have heard the saying “garbage in-garbage out”. It was a phrase developed for software engineers, meaning, if you enter garbage data into a software program you will get garbage out.
I Ike the modified version of “garbage in-gospel out” because it reminds me the output I get from my structural analysis program is only as good as the assumptions I enter into the software. Too often we believe the computer print out as being “gospel” or the absolute truth.
There used to be a school of thought that mandated an engineer only use software that he or she created. That way the engineer would know all the limitations of the software and account for unknowns with a little more conservative design.
Why do I bring this up, well, I had a meeting today about camber in prestressed pretensioned concrete beams. Specifically about how to get closer to the “actual” camber deflection dimension.
The problem in determining camber for long PPC beams is knowing the exact concrete mix properties and the initial and 28 day concrete compressive strengths. Without this information they best you can do is approximate the beam camber and use methods in construction to account for variances.
But you don’t necessarily have this information when you design the beam and prepare the bid documents, months before a letting.
Precasters typically use hot mixes (strengths about 20% above the design strength) so they can pour beams and strip them in a one day cycle. Quick turn arounds mean more money but cause me some problems in my design.
Say I ask for 7000 psi initial strength but I actually get 10,000 psi from the factory. Fine by me, but here is the point. Don’t ask me to calculate a beam camber within 10% of the actually camber based on my design strength of 7000 psi. Either live by the limitations of such a system with some realistic error bars or readjust the camber numbers after the beam strengths are known. (Not blaming precasters, I used to be one)
You cannot get accurate camber numbers out from a computer program unless you put accurate strength numbers in, so realize that and live with the fix in the field.
Otherwise, GIGO. See I got there.
I was watching this video and thinking if engineers designed this it would be square and have very small windows.
Maybe a rating system, like LEED, would spur momentum in the bridge industry? I know a number of organizations are trying to get one into the infrastructure marketplace. ASCE has Envision, the FHWA has Highways for Life, and the Illinois DOT has the I-Last system.
Maybe it would help if we competed for points?