BCF-Shear force at column face - Seismic provision

Dear Admin,

I am designing extended end plate connection for IMF-frame (AISC-LRFD) with seismic provisions (AISC-DG4 & AISC 358-05). 

Regarding to the provisions given in the aforementioned standards and report calculated by the RAM, I have several questions:

- plastic modulus of UB 406x178x67 beam should be Z=1346cm3 (as per BS section table), Z=15000cm3 (RAM)

- why gravity load component of shear force is equal to zero (Vg=0kN)

- distance between plastic hinges is obtained how?

Please refer to attached document.

Best Regards,