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 JAE 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. driftLimiter

    Valid Pin Boundary Condition?

    I find it very insightful human909 not pedantic at all :D
  2. driftLimiter

    Valid Pin Boundary Condition?

    where is human909? Im curious to see what they would say to OP. @duckhawk, remember that stiffness 'attracts' load. But also that ultimate limit states can aid our design process. Sure the connection exhibits some moment stiffness as others have indicated, but as you keep increasing that...
  3. driftLimiter

    ASCE 7 wind load for round irrigation tank

    In this equation its the 'projected' area. Meaning you project the surface area to a single plan. My read is that there are no windward and leeward components to account for when using it. Your second question is more interesting. You could treat it like wall that is open to atmosphere and compare.
  4. driftLimiter

    Odd Vertical Bracing

    If resisting seismic loading in SDC D or above, I think this would be difficult using prescriptive design per AISC. Do the beams in your diagram represent floor levels ? The type and ductility of this frame needs to be addressed if SDC D or above. That is a pretty significant hurdle.
  5. driftLimiter

    How to attach concrete buttress wall to toe side face of CMU retaining wall?

    Sketch please. and Loading information if applicable.
  6. driftLimiter

    Ultimate vs. Allowable Passive Pressure - which to use with a safety factor

    1802.1 just says that allowable pressures shall be used with allowable stress design load combos. Though I haven't yet had a geotech provide ultimate values, there is precedent for using them for foundation at least in ASCE7-22 12.13.5. Granted this section is in reference to seismic loading...
  7. driftLimiter

    Steel Vierendeel Truss End Connections

    Also your model has slip at one end and I would be looking to detail it that way or investigate the consequences of locking it in. I like the idea of a simple shear tab on the top chord and potentially another shear tab at the bottom chord perhaps with slotted holes.
  8. driftLimiter

    Best practice for connecting existing trusses and rafters to a proposed I-beam header.

    Looks like one of the property brothers designed this.
  9. driftLimiter

    Aluminum Design - Unbraced unequal leg angles in bending

    They have examples for unsymmetrical sections in flexure also 'open unsymmetrical shapes in flexure'. This should work for your unequal angle leg.
  10. driftLimiter

    Steel Cranked Beam End Supports

    I worry about this until I see the lateral support deflection. Get it small enough and I stop worrying about it.
  11. driftLimiter

    Deciding the lateral force resisting system.

    The slab needs to serve the role of drag strut collector. Some assessment of the tension and compression capacity of the slab as a strut/tie needs to be performed. There are different approaches used, some add supplemental reinforcement while others use the slab distributed reinforcement over a...
  12. driftLimiter

    ASCE 7-16 15.4-6 - Approx. Seismic Period Follow Up

    It is odd that you are saying gravity loads cause lateral deflections. The only reasons I can think of that that would happen are if you have a lot of P-delta or If your lateral system supports dead load (thrust typically from non-vertical gravity load resisting elements). First I think you...
  13. driftLimiter

    Bolt Hole Bearing Concerns Under Purely Axial Eccentric Load in Timber Connections

    Free body diagram. Can you use two plates on the sides of the wood beam instead so that the bolts are in shear only?
  14. driftLimiter

    ASCE 7-16 Use of Amplification factor Omega

    While I agree with your conclusion, I'd like to make a somewhat nuanced distinction on your response... "I think an inverted pendulum is a special case of a cantilevered column system" - No its just a slender cantilever structure with more than 50% of the mass concentrated at the top. Inverted...
  15. driftLimiter

    ASCE 7-16 Use of Amplification factor Omega

    If the source of lateral resistance is single columns bending about a fixed base you should use special detailing for cantilevered columns in my opinion. I do not believe that inverted pendulum and cantilever column systems are mutually exclusive.
  16. driftLimiter

    ASCE 7-16 Use of Amplification factor Omega

    I agree special foundation detailing and overstrength requirements are applied to cantilever column structures, and no such provision is written for inverted pendulum structures. I would refer to section 11.2 to verify that your structure doesn't qualify as a cantilever column system. By my...
  17. driftLimiter

    Gusset Base Plate design at brace location

    Some internal QA/QC is needed on your end before you can address the issue. A good free body diagram of the forces coming into the joint should give you the answers you need. The baseplate needs to transfer all of the member forces to the foundation. There shouldnt be a 'huge' force that you...
  18. driftLimiter

    Oversized hole considerations for anchoring overhead conduit supports - Unistrut P2073A Post Base and Hilti HDA-PR M10 undercut anchors

    I think this is the key thing for the OP. You need shear resistance, but can you tolerate some movement at the support in the design event. If the shear is only for EQ that makes sense, if its for some other types of loading maybe not.
  19. driftLimiter

    Diaphragm transfer forces

    The Fpx is based on the inertial forces from that diaphragm level. The transfer forces don't show up in that as we calculate both Fx and Fpx by each diaphragm level and do not include any contribution for forces from above. Basically the procedure is set up assuming that the inertial force is...
  20. driftLimiter

    Diaphragm transfer forces

    After reading Pham's reply alongside mine I think a sketch is useful The first sketch shows what I was saying about full length collector, full depth load application. For a 2d diaphragm model, this is the same thing as a point load. Second case shows what I think you were proposing as an...

Part and Inventory Search

Back
Top