Thankfully, there is only a small chance that the dinosaurs will be able to gain access on the ground or 2nd floor, as the doors are sturdier and smaller. Also, all entrances are invariably packed with frosh, adding an additional blockade to the dinosaur's advance, as well as slowing them down to eat the bodies. If it comes to a battle on the first or second floors, the software engineers will form the vanguard, as they are likely the most fit, and nobody cares much if they all die. Combinatorics/Optimization and Applied math students will make up the body of the force, with pure mathematics taking up the rear, as they will be unlikely to be able to do much, plus are too skinny to be good eating. If the structure of the defence collapses, a retreat to the sixth floor will be called. The plan followed from this point will be the same as if the dinosaurs gain access via the eighth floor.
Presuming the dinosaurs gain access on the eighth floor, the first step is to evacuate all people in the building to the sixth floor. Once on the sixth floor, the next step is to prepare traps for the dinosaurs. Since the sixth floor is a huge maze, it should be relatively simple to avoid the dinosaurs while creating the traps. Also, since dinosaurs cannot read floor plans, it is plausible that many of them will die of starvation before escaping the sixth floor. At that point, it becomes a game of avoiding the dinosaurs while trapping them in offices and starving them, while waiting for rescue from other faculties. Under no circumstances should anybody try to escape to the lower floors; those will be full of dinosaurs. If anything, attempt to make it to the roof and signal for help.
That was the dinosaur siege plan that I have developed. Hopefully it will never have to be used, but I'm not too concerned since I'm a pure math student, and would thus be at the rear.