(517) 403-6875 e-mail us

  • Sample report of crane bracing investigation


    CRANE BRACING INVESTIGATION

    I. Purpose of Investigation:

    At the request of contractor, Thomas R. Price P.E., of Structural Solutions LLC inspected
    the owner's facility for the purpose of analyzing and making design recommendations regarding
    the crane system bracing, and a previous building modification which raised one crane runway
    24", using column stubs.


    II. Description of Building:

    The building in question is a metal building manufactured by an MBMA manufacturer.
    The building is a 180' wide by 220' long x 28' eave gabled roof building. (ref. Fig.
    A). Two 60' wide overhead crane systems run the length of the building.


    III. History:

    Manufacturer calculation package indicates a 1993 design. At some point, the north crane
    bay runway beams were raised 24". Excessive building movement has been observed by occupants,
    which in part, has led to this investigation.


    IV. Referenced Documents:

    Manufacturer calculation package dated 1993. Job # 0000-00

    Note: Manufacturer construction drawings were not available.


    V. Field Observations and Notes:

    The inspection took place between 3:00 pm and 4:30 pm. Our comments relative to the
    inspection of the crane system are listed below.

    1) On at least one crane beam, cracks in some of the cap channel to beam welds
    were observed. This matter is being treated seperately, and is outside the scope of
    this report.

    2) Various crane and wind rod braces were observed to be excessively loose, and
    missing altogether. An earlier letter from this office calls for replacing all missing
    braces, and re-setting all braces to proper at rest tautness. The instructions in this
    letter, combined with the provisions of this report, should remedy the longitudinal
    bracing and movement problems currently experienced.

    3) The stub columns used to raise the north runway 24" lack longitudinal bracing.
    The details of the stubs were noted, and recommendations are made below.

    4) In reviewing the runway beams for recommending a solution to the cracked
    welds, It was revealed that the crane bridges need to be spaced further apart
    in order to avoid overloading the runway beams. The Manufacturer calculations call
    for a minimum 16'-0" spacing between adjacent cranes, center to center of wheels.
    Spacers to this effect should be installed immediately.

    In addition, it appears that the beams may be inadequate for the AISC design check
    on sidesway web buckling. Further investigation into the runway beams, bridge
    spacing, and posted crane capacity is strongly recommended.



Contact Information

Telephone:
(517) 403-6875 
FAX:
(517) 403-6875
 
Postal address:
 
Structural Solutions LLC
1200 Troon Ct. SE
Grand Rapids, MI 49546
Electronic mail:

General Information:     ssllc.tp@mail.com

[ Home ] Engineering Services ] Gallery of Projects ] Request For Quote ] [ Resources ]

Copyright 2012 Structural Solutions LLC, 1200 Troon Ct. SE Grand Rapids, MI 49546  Kent County