Reinforcement for open excavations - provides temporary side protection from rocks using vertical plates permitting introduction of tubular coffer pieces

摘要

The system is for use in open excavations in crumbling ground. It consists of working forward and placing end to end tubular coffers (63) at the bottom. Vertical panels (41), extend the entire height of the excavation and are held firmly to deflect all rocks ahead of the work. A shaped frame (18) is held by side shields and front cross stays. This holds the coffer parts which are carefully joined with seatings provided. The spaces between the coffer and the ground are finally filled in with concrete.