The bolt group in that connection is eccentrically loaded. It can be analyzed using linearly elastic methods like you learned in Mechanics of Materials class.
Each bolt has a shear component from the direct shear.
Each bolt also has a shear component from the moment. It is a pure torsion problem. In the AISC Manual, the polar moment of inertia is given as shown below.
Steel design textbooks often discuss this. Look for eccentrically loaded bolt groups, "elastic method" or "vector method."
