In a large bowl, mix 2 1/2 cups flour and the salt. Using your fingers, blend in the butter until the mixture resembles coarse crumbs. Sprinkle in the ice water and mix until the dough just holds together. If necessary, mix in 1 tablespoon more ice water at a time.
Turn out the dough, gather into a ball, then halve the dough ball. Pat each half into a disk, wrap with waxed paper and refrigerate for 15 minutes.
Position a rack in the lower third of the oven and preheat to 400 degrees . On a lightly floured work surface, roll out 1 dough disk into a 13-inch round. Roll the dough onto the rolling pin, then unroll it over a 9 1/2-inch pie pan. Press the dough into the bottom of the pan, letting the excess dough hang over the edges. Refrigerate while you continue.
In a large bowl, combine the remaining 1 tablespoon flour, the sugar, tapioca and cinnamon. Add the blueberries and toss to coat. Spoon the mixture into the chilled pie shell.
On a lightly floured work surface, roll out the remaining dough into a 13-inch round. Roll the dough onto the rolling pin and unroll over the filling. Trim the excess dough, leaving a 1-inch overhang. Roll up the edges of the crusts and crimp.
Cut three vents in the center of the pie and bake until crisp and golden, about 1 hour and 10 minutes (if the top is browning too quickly, tent the pie with aluminum foil). Transfer to a wire rack and let cool completely.