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  • 1.  Mass Timber Moment Frame

    Posted 8 days ago

    Despite increasing scale and scope of mass timber construction, we are still relying heavily on steel and concrete for lateral load resistance in wood buildings.  Timber braced frames have now been implemented in contemporary buildings and have strong historical precedent.  One system that I haven't seen discussed is a mass timber moment frame.  Perhaps there is good reason for this, but let's entertain the thought.  There are certainly instances where architects might want the openness of a portal frame in timber.  Do you think a timber moment frame is possible?  What are some technical concerns that would need to be addressed?

    Here are a couple that come to mind:

     - Connection slip amplified over the depth of a beam or column could result in large rotations before engaging an attached member.  Anyone who's checked story drift on a light-frame shearwall with an unfavorable aspect ratio knows NDS can be very punishing in these applications.
     - Orthotropic properties could cause issues transferring moment between horizontal and vertical frame members. - Long-term cross-grain shrinkage could result in loss of restraint as bearing surfaces which are initially flush pull away.  Perhaps some sort of take-up device could be developed to prevent this?

    Eager to hear everyone's thoughts!

    Christian Parker P.E., M.ASCE
    Structural Project Engineer
    Washington DC

  • 2.  RE: Mass Timber Moment Frame

    Posted 2 days ago

    Hi Christian, Definitively, timber should be a material to be considered more widely soon. Here I found this interesting video of what is being made in the USA: https://www.youtube.com/watch?v=gEewgo99tRc

    The European experience (https://www.youtube.com/watch?v=x6JTJWY_uag) and East experience (joint or connections: https://www.youtube.com/watch?v=OJ8V_rzwxh0) should be noticed.



    Andres Guzman D.Eng., MEng, Ing., M.ASCE
    Associate Professor

  • 3.  RE: Mass Timber Moment Frame

    Posted yesterday

    Check this out




    Olaf Faber P.E., M.ASCE
    Senior Engineer

  • 4.  RE: Mass Timber Moment Frame

    Posted 23 hours ago


    I think there are many examples of glulam moment frames already. I know that extensive testing in Europe has been done on them. We have conducted some studies on moment connections with embedded steel plates.

    I don't think CLT would be desirable for the frame parts since the two-way action of the cross-layers does not really contribute to frame stiffness. Glulam and LVL are much better choices.

    Daniel Hindman P.E., M.ASCE
    Faculty Advisor
    Virginia Tech
    Blacksburg VA