Cut slopes are usually Ok at 1:1 but fill slopes need flatter grades of 2:1 or even 3:1 for re-compacted material. But where would you get more material to fix your borrow pit? From the borrow pit borrow pit?
I think your borrow pit design might be similar to a waterway design (at low water...
Deciphering the code:
I am using RISA 3D to design a 5' high x 18' sq steel equipment platform in SDC D. I want to use a non-concentric braced framed frame system amounting to "knee braces" off the column base to the beams at 45o angle. I found that in AISC 360 C1.3a such a system is to be...
Q: If I add L's or C's below a raise slab to compensate for cut rebar, have I done any good? Assuming this is the tension face have I not just weakened it further by adding mechanical anchors.
I have a project at an old 1926 storage facility building (in a high seismic zone). A cellular...
Ah fall protection! This is may not be an OSHA requirement but you feel it is needful. I'm not aware of toe kicks being install for use during construction but a temporary toe kick as suggested is an option. But, if you are serious about netting, then you might look at the netting used at...
Not running any numbers but start here: Stiffen the stiffer plate by adding a "flange" on the outer edge and try material sizes commensurate with the beam it is to carry. You might even consider fabricating this "corbel" out of a piece of the that WF size.
I'm working on a project with an exposed mat foundation - 30" thick. It will be subject to freeze thaw cycles. I plan on using 3000 psi w/ 7% AE. I have a few questions on what more I can do to ensure durability.
[ol 1]
Would a concrete sealer be of help for the slab?
And, I will need some...
To StevePE,
Yes. While tension only bracing is a design approach where the dynamics of a seismic event will impose a reversing transient load, the reality under the D+S condition is the columns have an axial deflection of -0.127" and all braces will go into a constant overstressed compression...
Thank you for your thoughts and advise.
Yes, I agree the braces should be installed before the equipment dead loads are applied otherwise it's just a house of cards. A little further reading and I see I cannot use short slotted holes in the braces - only oversized holes.
[ol 1]
I ran the D+L...
I've designed an OCBF equipment platform in the Tahoe area where the snow load is 230 psf. While the "X" bracing utilizing L3x3's works well for the lateral design (as tension only or Euler buckling members), if I consider the compression they would "see" in the D+S case they are overstressed...
Hello All,
I have a project on tribal lands in Nevada where BLM is insisting on no soil disturbance i.e. NO foundation!!!.
This site is on a mountain top where high winds have ripped some existing equipment from their anchors. So, this time they came to an engineer for a design
The new...
Is asphalt paving a suitable material to be considered surface restraint? Even a small concrete pad could be questioned as the mechanism of restraint is relying on friction between the weight of the slab and ground surface and/or passive pressure on any locked in footing around the slab...
If your antennas are close mount you may not need to consider wind loading on the antenna opposite your wind direction but, if you exceed the distance allowed for shieding then, yes, you need to consider it and a reduced wind force is permitted depending on the amount of shielding provided by...
I don't know the history but S shapes are used in cranes and trollies. Here the load is applied directly to the bottom flange. The S shapes are better suited for this use having a tapered flange, the section modulus of the flange increases with the bending moment.
Thanks for the responses - good food for thought. I already replaced a catwalk that was rusted and deteriorated on an "abandoned" water tower. But in that instance I was able to redesign new elements based on today's standards and stiffen the remaining cantilever supports. I had not considered...
I (sole proprietor) work in the cellular industry where the catwalk rails of elevated water tanks are often used to hang antennas. These antennas that once weighed as little and 14 lbs each, now weight 97 lbs with pipes and mounts. With 3 carriers x 4 antennas each, failure has occurred on one...
Ok, I think since BIM programs are more complex, cost more, and are harder to learn, there is a place for both 2D & 3D drawing in the future - after all some of us still do hand sketches right? It all depends of the level of complexity and the need for coordination. In building projects as an...
As a solo engineer I appreciate this site immensely and today I need some advise on a contractor's idea.
He wants to completely chip way the concrete over a 10"x48" area against the wall of a parking garage floor to reveal the steel in the floor. After identifying the steel that can be cut and...
I'm facing a "new to me" problem and I would appreciate peer review on this approach:
I have an irrigation canal that needs to cross a drainage canal - clear spans 70‘. The plan is to pipe the water across with two 42" dia steel pipes. See attached drawing.
I've encorporated a...
