Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations waross on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Recent content by Lesali

  1. Lesali

    borrow pit design - soil eroded during construction

    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...
  2. Lesali

    Steel Knee Braced Frame & R value

    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...
  3. Lesali

    Core compromised 2 way slab

    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...
  4. Lesali

    Fall protection for tools?

    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...
  5. Lesali

    Stiffener Plate Design

    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.
  6. Lesali

    FREEZE THAW PROTECTION FOR EXPOSED SLAB, JOINTS AND GROUT

    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...
  7. Lesali

    Overstresssed Bracing for D+S

    Oops, I mean SteelPE - sorry
  8. Lesali

    Overstresssed Bracing for D+S

    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...
  9. Lesali

    Overstresssed Bracing for D+S

    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...
  10. Lesali

    Overstresssed Bracing for D+S

    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...
  11. Lesali

    BELLED PIER, ACP,vs NO FOUNDATION

    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...
  12. Lesali

    Sign Foundation

    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...
  13. Lesali

    Antenna loading on monopole design

    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...
  14. Lesali

    question: W-shape versus "American standard shape (S-Shape)" and flange tapering in genera

    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.

Part and Inventory Search