The bridge was probably origionaly designed with the assumption that the girders and slab were supported by falsework that was left in place until the slab concrete reached its design strength. When the falsework was removed the stress in the reinforcing steel in the bottom of the beams would...
According to an article in the August 10th edition of the Denver post, CDOT will now require contractors to submit an erection plan stamped by a PE.
http://www.denverpost.com/Stories/0,1413,36~23827~2324530,00.html
Try reposting this in the Bridge Engineering Forum. A little more detail about you question will help. I think you are refering to ASD and bending of plates about the weak axis. Is that right? In the AASHTO 16th edition section 10.32.4.2 allows using 0.8 Fy for stress in exteme fiber for...
Thanks Yakpol. I agree that it is an interesting topic. I was hoping to find some justification for not including shortening losses when the transformed section is used but so far I have not found what I was looking for. For now I will continue putting in the losses.
The lack of responses...
Thanks Qshake,
I also found an article in the November/December 2002 PCI Journal.
Conspan does not calculate elastic shortening losses to prestressed beams when using transformed section properties. Leap bases this on the PCI Journal article. I’m not sure if this correct or not. Any comments?
Does anyone know of a good reference that discusses the calculation of axial shortening losses for prestressed beams? I am particularly interested in comparing the calculation of these losses for non-transformed sections to transformed sections.
Thanks
The firm I work for doesn't allow moonlighting. If I received a resume that listed work from a side job it would raise serious questions. It might not go straight to the round file but it would be a problem. If you really want to list the experience consider listing it separately and noting...
There is a good article here: www.steel.org/infrastructure/bridges/integralabutm.pdf
If your bridge is on piles so that the piles can flex to take care of thermal movements integral bridges are the way to go. They eliminate expansion devices and bearings that cause problems. If your bridge...
Before you do anything stop and think. Is the job at your old firm the right job for you or are you just taking it because you don't like you current job? Remember there are other jobs.
If you decide to take the job, write a letter of resignation. Don't make it negative. If you have nothing...
V.O.D.
I just checked the CDOT "Standard Specifications for Road and Bridge Construction" (aka the Barney book). There is no requirement to have an erection plan developed by a professional engineer and no requirement to submit an erection plan. A special provisions may have been included in...
Good point about the contractor's experience or lack of experience Qshake. I read that contractor has done bridge work before, but it's hard to know how much was done by subs. They did have a sub for the steel erection on this project. CDOT uses a lot of prestressed bulb tee girders. The...
A standard note for Colorado Department of Transportation (CDOT) bridge plans reads "THE CONTRACTOR SHALL BE RESPONSIBLE FOR THE STABILITY OF THE STRUCTURE DURING CONSTRUCTION". I assume it was on the plans for this bridge. Does this relieve the engineer of legal responsibility? How about...
Brass will work for steel, concrete, prestressed concrete, and timber bridges. There are ASD/LFD and LRFD versions. It does ratings and can connect with Opis and Vertis. The price for either version is $2,500 with a $1,750 maintenance fee.
The downside is that the user interface is not the...
This sounds scary. I can see all kinds of problems from the foundation to the deck.
Do you have good foundation material? If you do, can you use masonry arches? This would be uncommon in the developed world because it is labor intensive but I assume labor is cheap there. If an arch has a...
Myint Lwin from the FHWA Resouce center presented a paper at a Steel Bridge Form in Denver about two years ago. He gave the following prices.
Material In-Place
Grade 50W $0.35-0.42 $1.00-1.25
HPS 70W TMCP $0.45-0.57 $1.15-1.45
From what I...
