researchers at ETH Zurich have let an autonomous excavator loose on a big pile of boulders and reclaimed concrete. The goal? To build a 20 foot (6 meter) and 213 ft (65 m) long dry-stone wall as ...

THE completion, just announced, of the great concrete structure originally known as the Boulder Dam ... and will be the retaining wall of a reservoir having a length of 115 miles and a total ...

He has now been retired for thirty-three years in Boulder, Colorado, after earning a pension from ... After the concrete dried, we built forms tied together with wires to make concrete walls to ...