The biggest deal when dealing with graduate architecture school applications is YOU and not your work. In essence, even if you have a B.Arch., your focus should not be on your most perfect renderings, but on those drawings and sketches that bring up your own personality and way of thinking. Through these sketches you will manage to build a narrative that will demonstrate to the admissions committee a) your PROCESS of thinking and composing, b) your ability to conceive IDEAS and develop them into tangible strategies and plans, c) your ability to precisely communicate in a few pages what you are thinking clearly and simply, and d) your personality as it is manifested in your design.
Try locking up your portfolio in a drawer for a week, and start from scratch, focusing on the ESSENCE of the work, which (in this case) is the process itself. Begin with your essay (Yes! the admissions essay), and use it as a road-map for the portfolio. Use the essay to analyze yourself and what you are, what you stand for, and what you want to achieve in your career. Then, develop a theme for your portfolio that you will be able to describe in a paragraph. Then, develop a narrative based on a) the theme, and b) the projects that you have available to show. This narrative will be how your strategy will unfold. Then, take each one of your projects and try to fit them in the narrative. For this, you will need to pretty much tell a story for each project. I do not mean sit down and write an essay for each. I mean use visual material like sketches, diagrams, mappings, sketch-models, etc, formatted and laid out appropriately, in order to tell your story. If you do not have this material, PRODUCE IT!!! There is no law (yet) against post-rationalizing and post-producing. If its ok for Renzo Piano to do it, then it is ok for you to do it too.