tallbridgeguy

I am scheduled to give a talk in August about the shear capacity of concrete columns in regards to the AASHTO 400 kip vehicle collision load.  So of course this lead me to revisit the “Modified Field Theory for Calculating Shear Strength of Reinforced Concrete Elements” which is the basis for most of the beta/theta factors in the new code.

In that paper there is a note about a software package called Response-2000. Quoting the website,

Response-2000 is an easy to use sectional analysis program that will calculate the strength and ductility of a reinforced concrete cross-section subjected to shear, moment, and axial load. All three loads are considered simultaneously to find the full load-deformation response using the latest research based on the modified compression field theory. The program was developed at the University of Toronto by Evan Bentz in a project supervised by Professor Michael P. Collins.

Response-2000 is able to calculate the strength of traditional beams and columns as well as or better than existing methods and, more importantly, is able to make predictions of shear strengths for sections that cannot easily be modeled today such as circular columns and tapered web beams.

I emailed Professor Bentz and he mentioned that over 33,600 engineers and students in 153 countries have downloaded this software! Wow, I am sure out of the loop but I guess I am now 33,601!

Professor Bentz is working on a new version, available later this year, called Response-2010. The new version includes the flexibility to use any stress-strain curve you want, allows for an XML input file and should be easier to use. Did I mention it was FREE? Professor Bentz was also kind enough to send me a few screenshots.

Professor Bentz explains,

The first shows the new main screen with a sample member in it.  The second shows how the new M-N interaction diagrams have all the points kept in them and thus we can examine them all and thus be fairly sure if we’re doing things correctly or not. The last shows a new mode whereby we can look at a particular depth and see how the shear is carried at that depth.  This isn’t well shown as a still image as it’s much more instructive to move the cross section up or down or to change the loads and watch the Mohr’s circles change.

So check out Response-2000.

So I am trying to learn to paint and of course I have to post my first efforts so I can see the dramatic improvement coming….say two week tops.(HA!)

Little 6″x6″ Apple study on board.

Okay I “painted” this yesterday before dinner. I spent 30 minutes using my new pochade box in the backyard. I tried to paint my reflection in the back door but the mosquitoes were crazy!

Anyway, this is another starting point. First painting outdoors.

Christmas in July?

Every state is facing the problems of a declining infrastructure. I often wonder how we ever got it built in the first place.

From DJC Oregon,

In a recent study released by a federal committee, the Oregon Department of Transportation reports that 1,665 bridges in the state are deficient. But that doesn’t mean all of those bridges are unsafe or that commuters need to worry every time they drive over one.

The majority of the Oregon bridges on the list did not end up there because they are structurally unsafe, but because they can no longer meet the demands of traffic that has increased as populations have grown.

The bridges are what engineers refer to as functionally obsolete, and according to a new report by the Committee of Transportation and Infrastructure in the U.S. House of Representatives, 1,188 Oregon bridges on the list fall into this category.

Sorry I ,have not blogged much lately, I have been busy being frustrated at work and at home. (teenagers, sigh, coworkers, sigh)

One of the things that continues to frustrate me is my quest to become a painter. Not a bridge painter but a fine Art kind of painter. I pretty much suck at oil painting but my long range plan is to become proficient by retirement age.

I hope to travel and paint. Hopefully selling a few to pay for paint and coffee…As an engineer I enjoy putting all the equipment together, reading how-to books by the bushel and starting a painting. Its the end product that gets to me, I’m not used to working hard and getting a lousy final painting. How do artists deal with the uncertainty of  having all their work end in mud?

So my question is, can my engineering left brain allow me to be artsy? Can my right brain grow enough that I can paint a passable flower? (A flower that will hang proudly in the retirement home bathroom?)

So help me out, is it possible to learn to paint if your an engineer?

Highestbridges.com is a website owned by Eric Sakowski, with the mission statement to list and personally verify the heights of bridges around the world. In addition to listing heights of bridges, Eric has posted some great pictures of the structures and interesting background information.

With 500 bridges listed, and none of them mine, I really have to move closer to the mountains…

Chiapas Bridge

Image by Grupo Triada

Not sure I understand the concept but Architect William Badrick is putting his pastels to good use. Here is his concept for a new Columbia River Crossing. And check out this awful idea…

Amazing graphics

In my previous post I inserted a quote about public involvement in projects
and how they affect the final structure.

The Happy Pontist responded with a great comment,

Over-reliance on public input to design seems to me to be indicative of a
huge lack of confidence on the part of designers in their own abilities,
not to mention a lack of guts on the part of those who commission us.

It strikes me as an American disease, as clients elsewhere generally
understand the difference between public consultation and public decision-making.
Design is inherently undemocratic – there are decisions to be made which are
rarely best made by appealing to the lowest common denominator.

Clients will only be given confidence to change if they are inspired by designers
with vision and who are able to articulate their ideas as persuaders of the public
rather than as merely there to accept public “wisdom” and implement it.

The only part of the comment I take issue with, is the contention this is an American disease.
State department of transportations oversee the majority of bridge projects and the heads of these departments are typically run by Governor appointed, at-will, don’t screw up, directors.

Their jobs literally depend on offending the smallest segment of the population. Which usually entails developing projects that are bland and unoffensive or hiring a consultant to take the heat if a project goes south.

(Hmmm I seem to be making HP’s point..maybe I should backpedal or go all in..)

Lets take the recent pedestrian bridges in Calgary. The first bridge was given to Santiago Calatrava directly by the city officials. Which lead to a large amount of backlash, which lead to the second bridge design becoming an open competition. City officials heard the public and responded, not with leadership but with a fig leaf and a bit of misdirection to take the heat off their earlier decision.

Unique public projects are incredible tough to get through in America but I would suggest this is the case all over the world when politicians are involved. I have to agree with HP that the best way to get something unique is with a designer who can persuade the public of their vision. But designers like that seem to be rather rare over here.

While I am waiting to watch the world cup, I reread an old article by Paul Gauvreau, The Three Myths of Bridge Aesthetics.

My favorite quote is the one about public involvement. While it is great to have the public in the picture, imagine what would happen if architects allowed a crowd to design a building….not a good idea…

There are no simple answers to the problems relating to public participation on bridge
projects. The problem tends not to be public involvement per se, but rather a mindset
that the primary focus of the design process must be transformed into one of building
consensus as quickly as possible.

When bridges are designed on this basis, it is unlikely that they will have the capacity to raise meaningful challenges to existing ideas, because their entire raison d’être is to conform rather than to challenge.