Builders of the U.K.’s tallest skyscraper, London’s Shard, will save valuable time by excavating its three-floor basement while slipforming the core. A novel machine is now at work, plunging columns into pile tops some 15 meters below ground to prop up the rising core as soil beneath is removed.
With the core on the critical path, “the month or two” top-down exercise is “giving us breathing space,” says Bob Gordon, chief engineer of the 310-m-tall building’s main contractor Mace Ltd., London. Piling began in March, but he expects the core to go up in November, well before the basement is done.