Micropile, allowable bending stress

[AllStructure]

Hi everyone,
I am designing a foundation consisting of micropiles (10" OD steel casing, filled w/ grout). Since my design assumes a fixed-head, i have to design the micropile for max fixed head moment. I am having difficulty to find what is the allowable bending stress specifically for micropiles. I know that AISC ASD allows 0.66Fy (lateraly supported "column"). Please include any references with your response.

Thank you

 

[jdonville]

AllStructure,

Sounds like you need to generate a beam-column interaction diagram. Also, you should check with the geotech to ensure that you are working with the maximum loads (moment, shear), as these may vary along the length of the pile due to soil resistance and lateral displacement.

Jeff