In CAESAR II you would model this intersection the same as always. Things to watch out for are:

a) You have a 4 inch long segment of 1" pipe inside the 10" header that doesn't really exist. If this length significantly affects the flexibility of the branch, you need to use a "dummy rigid" element here.

b) Make sure you closely evaluate your connection with regard to the standard fitting types in the Code. CAESAR II only computes SIFs for fittings listed in the Code.