...a simpler approach could be to simply count the rim joist toward the header requirements.
For example, take the following design requirements:
* Required header span = 7'-6"
* Maximum header depth = 10"
* 2x6 wall framing
* Building Width = 28 feet
* Header supports roof, ceiling and...
I'm in the process of designing a new house that will be built in Southern Maine. Winters here can be pretty long and cold. Generally speaking, code requirements in this area specify setting frost walls about 4' below grade.
The house will be set on 8' foundation walls to provide a full...
The embankment is about 15' high and is along a river so we're trying to minimize in-water impact. We've also looked at 3:1 and 4:1 side slopes and, while the FOS for those options are are better, they still don't yield an acceptable FOS of 1.3. A toe berm could be constructed and would...
When it comes to estimating experience and judgement are a designers best tools.
That said, what is the estimated construction cost for replacing the bridge? If all else fails start with about 10% of construction as a total design fee (preliminary and final design). It's an old rule of thumb...
This may seem like an off-the-wall question but I'm going to ask in hopes of getting a few opinions.
Long story short I have a project that involves modifying an existing embankment slope that was constructed over very soft clay (Su values in the 100-150 psf range). The embankment modification...
Does anyone have a good resource for this? I'm looking for a listing of the most commonly-available angle iron sizes, and the maximum length they're typically available in
Thanks
I'm working on a bridge rehabilitation project that includes painting several riveted built-up steel girders. In several locations the girders exhibit areas of moderate to heavy pack/impacted rust. I've been researching various methods for how to best address these areas and thought I'd check...
I too am unsure why the bottom chords would need to be larger than the top chords. Based on the quick model I put togheter last night the snow load on the roof was requiring the top chord to be larger than the bottom chord (in my model the bottom chord acted primarily as a tension member).
In...
Hey guys, thanks for your input. I figured those would be the responses, but it's nice to get a second opinion or two!
I ran some numbers on this last night and was finding some rather large horizontal deflections at the truss supports. In addition, the connection design would be a bear. In the...
A contractor friend of mine has asked me to evaluate a conceptual roof framing idea he’s come up with for a single family residential home he’ll be building in Vermont. Most of the roof framing will be very conventional, but one portion of the home will include a cathedral ceiling that spans the...
Hello all,
I have a small favor to ask and am hoping someone here may be able to help me out...
I'm planning to construct a three sided enclosure around my home oil furnace. I've reviewed the clearance requirements from the installation manual, but I'd like to try to reduce them. In the manual...
When completing a 'typical' highway overpass design I've always been of the school of thought that complete and thorough design calculations are necessary and prudent. In other words, my design calculations closely resemble the scope and complexity of those shown in FHWA's two LRFD bridge design...
Civilperson - The AASHTO LRFD mandates a uniform bearing pressure distribution (over a reduced bearing area based on eccentricity) for foundations on soil. Foundations on rock are designed using a trapezoidal (or triangular) distribution.
Miecz - You've probably already seen this, but AASHTO...
I have checked a construction loading case - basically all loads except those from the superstructure.
To answer your other question, I've checked bearing, sliding, and eccentricity at the Strength limit state as required by AASHTO. I believe (from memory - my manual is at the office) that...
I've been tasked with designing a pair of stub abutments on spread footings for a highway bridge. I've developed a foundation design based on AASHTO's LRFD criteria that seems to make sense to me, but I'm looking for a quick sanity check.
Whenever I've looked at an abutment standard detail, or...
Not entirely sure what you're trying to protect here, but if you're putting a line of barrier in front of a bridge abutment be sure to place the barrer far enough away from the element to account for vehicle roll. If a tractor trailer truck hits the barrier, the truck will 'lean' in toward the...
Thanks for the link. I have seen that reference and refer to it frequently. However, it doesn't gives any definitive guidance on how to select wingwall orientation (the angle at which the wall flares back from the abutment seat).
On non-skewed bridges with equal rates of embankment slope in...
