Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

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

Search results for query: *

  1. moments

    Anyone familiar with this marking for a steel beam?

    To my eye it says BIR USA upside down and mirrored. Don’t know the reference.
  2. moments

    Elastic Seismic Design?

    I work in a relatively high seismic area, and when my office expanded, the company wanted the new building to practice what we preach, put the structure on display, and provide an immediate occupancy building performance to serve as a command center after a big earthquake. With those goals in...
  3. moments

    Please help

    The CA Civil Seismic Principles Exam, for better or worse, is largely a test of ASCE 7 seismic chapters. It is not much else than that. I recommend majorly refocusing your preparation for this test.
  4. moments

    Rebar as bolts in base plate connections

    I specify these regularly. More frequently in vertical surfaces, but that’s a minor point. They’re genetically known as “deformed bar anchors,” and for non-seismic loading, look into “D2L bars,” for seismic “D6L bars.”
  5. moments

    ACI 318 Boundary Element

    When you say 0.2fc stress, don’t forget that the load was determined with an R factor. The stress check option for is intended to make for an easy hand calc to answer a yes/no question whether special boundary elements are required, not represent the actual seismic behavior.
  6. moments

    Would you stamp this?

    My typical role in these cases is that of base building engineer reviewing design-build stair submittals that are required to comply with the seismic drift provisions. We’ve been happy to coordinate with the stair designers by reviewing applied loading imposed by seismic force and displacement...
  7. moments

    Noob Steel Buildings Question

    Concrete over metal deck floors. Shear studs on the beams into the deck for composite action. This, instead of light framed infill. Spans are on the order of 10 ft. between beams for unshored composite slab systems.
  8. moments

    Effective Wind Area - ASCE05

    The magnitude of pressure uses the effective wind area, but a manual calculation of line loading based on that pressure would use the width tributary to that member.
  9. moments

    ASD Safety Factor

    First, you correctly answered your own final question about a safety factor for cold formed steel lateral systems per AISI. Second, FYI, all the hot rolled steel design safety factors (ASD) or resistance factors (LRFD) are clearly layed out in the Specification (AISC 360) which is included as a...
  10. moments

    Gypboard equivalent Plywood in wood shear walls. and strap bracing

    You're looking for Sureboard. It's a sheet metal plate bonded to gyp board. There's an evaluation report giving the shear wall capacities, which are comparable to wood structural panel sheathing. http://www.iapmoes.org/media/20779/er_0185.pdf
  11. moments

    Torsional Irregularity

    There's a 2018 FEMA / NEHRP report, P-2012 “Assessing Seismic Performance of Buildings with Configuration Irregularities - Calibrating Current Standards and Practices” Direct PDF link is here...
  12. moments

    seismic isolator vendor

    We've had great experience using friction pendulum isolators from Earthquake Protection Systems.
  13. moments

    What's the purpose of these concrete beams and columns in Wall?

    I have seen this type of wall construction in San Francisco. Also, for that same project, the adjacent buildings were constructed in stages over years from one end of the block to the other, so the exterior side walls became progressively interior. The common wall was used to support both roofs...
  14. moments

    Wood Shearwall Sheathing Field Fastening Pattern

    The main function of the field nails is to preclude panel buckling, allowing for the edge nails develop their strength and ductility. As already pointed out, for shear wall design using the SPDWS, the 12" vs. 6" spacings are prescribed within the capacity tables for various assemblies.
  15. moments

    Simpson Hold-down Nominal Capcities

    Look at the notes to the designer in the front of the catalog, and they tell you the factor of safety applied to the nominal capacity is 3.
  16. moments

    3 Wythe Brick Wall Removal

    Wheels, Here is a video of some brick wall demo with installation of twin steel beams, for your entertainment. The action starts around the 16 minute mark. https://youtube.com/watch?list=PLG444oOvpFDtkeoq26jXRLA-IHm_4RsGk&v=YXQoCUFvvnU The gears in your engineer mind will be spinning as they...
  17. moments

    WUF-W Connection

    Isn't it true that those welds became demand critical after the Northridge Earthquake revealed numerous brittle failures at this location in steel moment frame?
  18. moments

    Joist Hanger using 1-1/4" Rim Joist as a Header

    Simpson has a technical bulletin about this. Their website directs to here for the current version: https://embed.widencdn.net/pdf/plus/ssttoolbox/a3vd04ksyr/T-C-RIMBDHGR16.pdf?u=cjmyin Per this bulletin, you can use LUS hangers on rim board by taking 0.84 of the tabulated capacity.
  19. moments

    Stepped Foundations and Shearwalls

    Keep in mind also, with discontinuous shear wall chords you are required to apply the overstrength factor to the overturning loads.
  20. moments

    NDS 2005 shear values

    I agree with the response above, but I think OP's question is not a confusion between ASD and LRFD, rather between demand and capacity. Multiplying by 0.7 (a.k.a. dividing by 1.4) is the load factor from the ASD load combinations for earthquake forces. Dividing the tabulated nominal shear...

Part and Inventory Search

Back
Top