Fluted steel column capacity
Fluted steel column capacity
(OP)
The 8'6" steel fluted column in these pictures is in service in the top floor of an old factory (1900+/-) building that was converted into condominiums in the early 1990s. It supports the roof structure of the building, but a client is hoping it's got the capacity to support one corner of a new roof deck.
Anyone got an idea where I might find the structural properties of such an item? (crickets chirping) And if not, anyone want to tell me how they'd approach calculating its capacity?
There are no markings on the column other than the fluting and the decorative top to tell me what kind of steel it may be. It could be wrought iron for all I know, but shows no grain or texture.
Anyone got an idea where I might find the structural properties of such an item? (crickets chirping) And if not, anyone want to tell me how they'd approach calculating its capacity?
There are no markings on the column other than the fluting and the decorative top to tell me what kind of steel it may be. It could be wrought iron for all I know, but shows no grain or texture.






RE: Fluted steel column capacity
RE: Fluted steel column capacity
Thanks!
RE: Fluted steel column capacity
Load up the structure to simulate live load and safety factor.
Measure the deflection difference and verify that there is still a gap (column is still taking all of the load).
RE: Fluted steel column capacity
RE: Fluted steel column capacity
RE: Fluted steel column capacity
Cast Iron
Modulus of Elasticity at 75% of limit load, (must be tangent modulus) between 700000 and 1300000 kgf/cm^2
Breaking (limit) stress 150 kgf/cm^2 tensile action
Breaking (limit) stress 600 kgf/cm^2 compresive action
Working stress factor, as recommended by no less than PONCELET and Morin, 1/5 to 1/4 of the limit breaking stress, so
Allowable stress (tensile) 30 to 37.5 kgf/cm^2
Allowable stress (compression) 120 to 150 kgf/cm^2
What above as per
Materiales de Construcción
Antonio Camuñas, Guadiana de Publicaciones 1970
Quite likely the above values of the safety factors had some consideration, yet, not knowing, better not count on it, or start from breaking stresses and adjudicate your own safety factors anew and some statement of buckling effects.
RE: Fluted steel column capacity
RE: Fluted steel column capacity
(both laterally X and Y in plan restrained hinges)
7.5 to 7 cm diameter cast iron column
L/1000 initial imperfection, Pn=13.58 tonne
L/500 initial imperfection, Pn=6.96 tonne
L/200 initial imperfection, Pn=2.82 tonne
limit axial loads as per some updated check more or less to modern codes ...
column strength reduction factor to be multiplied and be checked against factored loads ... not a good prospect.
RE: Fluted steel column capacity
RE: Fluted steel column capacity
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RE: Fluted steel column capacity
RE: Fluted steel column capacity