Gaudí’s observation that God did not “build” in straight lines.
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What is remarkable about this ethereal forest is its deceptive simplicity. Well before sophisticated, computer-driven calculations, Gaudí had discovered “that an interlinking of parabolic arches and slanting columns can bear the hefty weight of even large vaulting masonry” (Zerbst 208). This allowed Gaudí to do away with the famous Gothic flying buttresses, which he considered “crutches.” Instead of using the flying buttresses to prop the outside walls which in turn supported the weight of the roof, Gaudí used parabolic arches inside the church to transfer the weight inward onto the top of the parabola (curve) thereby supporting the roof directly from below.
The soaring pillars are made primarily of four different kinds of stone, varying in colour and load-bearing strength. The strongest stone, the maroon-tinted porphyry, supports the crossing, the point where the east and west transepts meet the nave. The four columns here will also provide the main support for the projected Christ tower, the tallest of the eighteen towers, at 558 feet (170 metres). Other stones used are local hard Montjuich stone, granite, and basalt.
No flying buttresses, just loads distributed on lightweight parabolas made of tilted columns.
http://www.spainthenandnow.com/spanish-architecture/gaudi-sagrada-familia/default_265.aspx
