No, that isn't a U-brake, that's a sidepull caliper. A u-brake would have two arms that pivoted about studs mounted somewhere above the rim. About the only way to adjust that brake for pad clearance would be to loosen the mounting bolt and rotate the block that the spring fits into. I believe Sheldon Brown does explain how to do that in his article on sidepull brakes, in case my explanation is a little unclear.