Integrated Buildings & Structures

  • 1.  Church Structure

    Posted 07-28-2021 01:33 PM
      |   view attached

    Drawing attached is a church structure. This column alignment is this a good practice. Two storied 8m span 5bays are there. The ground floor is done. Columns are raised for first floor. Theory and practice the difference.  Please clarify my doubt. 



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    Alex Thomas R.Eng, M.ASCE
    CochinAlexThomasR.Eng, M.ASCEIndia
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    Attachment(s)

    pdf
    THAMPI-Model.pdf 1.pdf   43 KB 1 version


  • 2.  RE: Church Structure

    Posted 08-01-2021 06:40 PM
    Dear Alex, I assumed that you are working with RC. How do you predimension the structural elements? What are the specifications for foundation (soil strength and recommendations from the geotechnical expert)? The plans are feasible but you should check how to solve the beams connecting the 15 m bay (type, materials, reinforcement, shape).
    Regards,
    AG

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    Andres Guzman Ing., M.ASCE
    Associate Professor
    UNIVERSIDAD DEL NORTE
    Barranquilla
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  • 3.  RE: Church Structure

    Posted 08-01-2021 10:04 PM
    Using thumb rules I have decided the dimensions of the beams and columns
    From previous structures it had been detected that if we gave the columns with considerations of least radius of gyration, lead to move the structure to and fro due to live load
    Here's an old practice to give corner columns L shaped, shall be giving T shaped columns 





  • 4.  RE: Church Structure

    Posted 08-02-2021 09:13 AM

    Dear Alex, columns could be dimensioned with dead and live loads predicted following local regulations and recommendations. Considering the column height, you should deal not only with mechanical strength but also with buckling strength. The critical load for buckling requires a high radius of gyration (Pcr = (pi)^2*E/(k*L/r)^2 ; being r = root(I/A)), so the slenderness ratio (k*L/r) decreases and so, increasing Pcr.
    The best shape for a column should be the one that accomplishes both limits (mechanical strength and buckling strength). You have to consider that no predominant directions for inertia and radius of gyration are preferred (circular column); nevertheless, considering limitations of useful area and forms to construct that column, rectangular shapes or other shapes could be considered. "L", "T", and "I" columns could also be used, but always considering limitations of area (to take advantage of available spaces in the plans).

    Regards,
    AG



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    Andres Guzman Ing., M.ASCE
    Associate Professor
    UNIVERSIDAD DEL NORTE
    Barranquilla
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  • 5.  RE: Church Structure

    Posted 08-03-2021 09:40 AM
    Hello there,

    Have you tried to model the corner columns L-shaped to increase the radius of gyration in each direction?  You also have to check the effects of building torsion on each column i.e. minimum if the structure is symmetrical for EQ and torsion due to critical crosswind.

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    Richard Ochotorena P.E., M.ASCE
    Architectural Profiles Limited NZ
    Hamilton
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  • 6.  RE: Church Structure

    Posted 08-04-2021 12:15 PM
    Keep in mind that the highest design-wind-load conditions typically occur at the corners.  Since the design does not appear to have any structural columns in the end walls, the corner columns may need to be strengthened to provide adequate torque resistance.  If there is an option to add structural columns to the end walls, even if they are only a few feet in-board of the corners that could provide significant structural benefits.  Exterior buttresses might be another option.

    Your description did not discuss the first-floor structural design.  Will it be designed as a moment-resisting rigid diaphragm?  If so, it can contribute to the torque resistance, but the transfer of those forces into the columns needs to be accounted for in the column sizing, bracing, connections and anchoring.

    If seismic loads are a concern, the most highly loaded columns may be different than those identified by the wind-load analysis.

    Bruce Clarke, P.E. M.ASCE, SECB
    BH Clarke Engineering, LLC

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    Bruce Clarke P.E., M.ASCE
    Owner
    BH Clarke Engineering, LLC
    Belmont MI
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