So we did some analysis here and have worked out that Cb of 1.67 appears to be appropriate as the restraining force required is relatively small (1% of applied load).
We also did an analysis using the AISC alignment chart and have worked out that for W6 pile sizes with 4" wide flanges the K is...
KootK appears to have a good understanding of this.
So the top rail (torque tube) provides "some" restraint to the top of the piles from moving in the weak axis - there is a bearing at the top of pile but due to friction with the dead weight it should provide 50 lb of lateral restraint - do you...
