double angle lintel

huangyhg

double angle lintel
hello,
i am designing a double angle lintel for a 9' opening in an exisitng clay brick wall. the wall is fairly large, 16" thick solid, about 50' tall. i am going to use a double 8x8x9/16 angle to jacket the 16" wall.
loading is 1000 plf unfactored applied to the horizontal legs of the angles - assuming arching action carries the loads 6' above the lintel.
my question concerns the eccentric loading of the angles. i am going to use a weld plate below the horz angle to prevent rotation of the angles. 1/2 x 6 x 12 with full weld in the field after the lintel is installed. i checked the weld and plate ad seems very consv. against:
p=2800 lb applied 4" from heel of angle
m=2800lb x 4" arm = 11,200 inlb
t=11,200 inlb / 2.2" (y from asd steel man) = 5100 lb
the plate and weld are very consv for this load, can anyone suggest further checks or confirm that my anaylsis is sufficient for this design?
correction: p should be 5600 lb 4" from heel, yeilding  11200 lb force applied to the weld plate