Steps

1. length of seat angle supporting the beam =bf
2. bearing length of seat angle (b) required at root line of beam=$\frac{R}{Tw\times(\frac{fy}{\gamma w})}$
3. Provide clearance=10mm
4. Assume size of seat angle on basis of bearing length as describe in unstiffened seat angle connection
5. outstanding leg of stiffner angle must provide the required bearing area outstanding leg must not exceed 14 E of thickness where E=$\sqrt{250/fy}$ to avoid the local buckling required local area is calculated Abr=$\frac{R}{fy/ymo}$thickness of stiffner angle should be more than thickness of web of beam supported
6. Due to stiffner seat angle is not flexible and bolt are connecting edge subjected to moment in addition to shear This connection behave like bracket connection
7. The eccenctricity bending moment and tention acting in a critical bolt commuted similar to bracket connection
8. Using interaction formula critical bolt is checked
9. The nominal angle provide top of the beam and is connected with two normal size of bolt on each leg of cleant angle