Hey folks,
I have a question from a supplier asking why we specify hot rolled steel sheet piling in accordance with ASTM A328 (or A572) but we do not mention cold formed sheet piling. Therefore our current specification prohibits cold formed steel sheet piling. It is my hope there may be an...
Colleagues,
I am a bridge designer so I deal with steel and concrete and big time loads so I just don't have a feel for typical residential wood design. I offered to help a buddy design or scope out what it would take to build a shed on his property. He has some grand ideas and I'm trying to...
Greg,
I developed a solution to a highway paving problem and now my collegue asked me to write a paper on it. Well, I wrote a bunch of stuff on my model and some others added a few things and submitted it for publication. a reviewer asked me to "cite" my source for a statement that automobile...
Hey fellows,
I am a bridge engineer so I infrequently get involved in doing things with differential equations. However, I have been asked to collaborate with a fellow from the concrete pavement arena to analyze/predict the effects of having a transition in the pavement thickness. We agree...
I have been asked to advise a bridge designer concerning the material used to build a bridge in 1959. The construction specs of that era indicate that the bridge should have been made from ASTM A373 steel (or ASTM A7 if not welded). The bridge plans indicate the deisgner asked for ASTM A373...
Hey folks,
I rarely get involved in means-and-methods in my job, but I am part of a group that has to review some specifics related to precast concrete panels. The panels will be cast flat and then raised from the forms by attaching anchors to one edge and lifting from the forms causing...
Hey folks. I am working on a project where the designer wants to weld a plate to a second plate to form a "T" shape and then he wants to load the "stick" of the "T" to the full capacity of the plate (e.g. this is part of an elaborate flange splice to a cross girder). I am concerned the "bar"...
This could be asked in several different fora, but I'm going to give it a shot here first.
We own a number of bridges, including several trusses. Most of these trusses are made of built-up riveted steel members. The sections of the trusses are assembled with very large diameter pins, often...
Folks,
We received certification paperwork for high-strength bolts to be used on our project. The fasteners have been dual certified to ASTM A325 and ASTM A490. The fasteners have been hot-dip galvanized. I understand there has been a long standing prohibition on galvanizing ASTM A490 bolts...
Due to a fabrication error, we are looking at a non-symmetric beam. This made me reflect on a philosophical question about design of bridge girders.
The exterior girder is non-symmetric due to the presence of the concrete slab with an overhang not equal to the effective flange width toward the...
I have read many things here where folks appear to think highly of electrical transportation. I don't think much of it because the energy needed is much higher than traditional solutions. On another thread, it was reported that only 15-20% of the input energy at an electrical power plant was...
I need to find a source for the standard shank and threaded run on A325 bolts. My AISC manual shows the head, nut and washer dimensions so I got that. What I need to know is for say a 2-3/4 inch long bolt, how much is threaded and how much is not. We have an installation under design that may...
I work at a DOT and we have thousands of poles supporting lights and signs. When I was in Grad School, we talked about using tuned mass vibration dampers to reduce vibration forces on structures. Our aluminum poles come with a device that sounds as if it may be one of these devices. However...
If I had a big financial grant I would study this and get a PhD or something, but since I don't I'd like to know if anyone has any thoughts on an intermittent failure we are having where steel posts are welded to baseplates and then failing in a brittle manner.
One of these situations exists...
Guys,
I recently returned from a steel fabricator we do business with. I now work in the fabrication inspection field having moved over from designing. Once the fabricator and his shift manager realized that I was not an arrogant designer, they started hitting me with all kinds of questions...
Guys,
I have been noticing several threads recently where folks with no formal engineering training have posted questions. For a time, earlier this year, I noticed most of these were answered, "You need to hire a structural engineer." I think this is the correct thing to do in most cases. I...
I am a bridge designer. I was talking with a pavement designer in the office yesterday. He said pavement is designed so the flexure stress is less than 650 psi. This is a much higher stress than we use in the bridge community. Can anyone verify this design limit and or enlighten me why...
I have been asked to inspect glulams ordered by my agency for a pedestrian bridge. The only portion of the QC at the plant I am concerned about involves locating finger joints (End joints) in adjacent laminations far enough away from one another or from a knot. The language in the code is...
I have access to left over 4x8 concrete cylinders. I have a nine foot high berm behind my house that serves as a poor noise barrier between me and the highway. I would like to terace the berm into three three foot high sections. It seems it should be possible to stack 4x8 concrete cylinders...
It is my understanding that precast prestressed girder plants strive to cast several girders in one long bed for economy. It is very sensible to me because one bit of labor to get the initial tension into the strands serves the requirements of many girders. However, this brings up a question...
