MecaStack considers effective length factors (K) for sections of a Self Supported or Guy WIre supported stack, depending upon the boundary conditions at each end of the riser section.  The specific values used depend upon which stress code is selected; however, here is a summary of the factors used:


Cantilever:

    Eurocode, Indian Code and BS 4076:  K = 1.0

    AISC 360 Code:   K = 1.0   (This codes is used when STS is selected, but for small diameters STS refers to AISC.  If we use a 2.0 factor then the stack fails nearly every time, and it seems very unrealistic; therefore, we use K = 1.0 which gives more realistic results).  

    All other Codes:  K = 2.0

Pinned-Pinned:
    All codes:   K = 1.0

Pinned-Fixed or Fixed-Pinned:
    Indian, BS 4076:   K = 0.85
    All other Codes:  K = 0.8