Semi-rigid arch for supporting underground gallery - has slidable H=section beams operated by hydraulic rams acting against bolted reinforcement plates

摘要

The semi-rigid arches are for supporting underground galleries. They are made of three or four parts which can slide for a short length and are supported by hydraulic rams during use. The arches are made of commercially available H section. The H sections are butted together and then the two parts are bolted through overlapping support plates. Reinforcing plates can also be added to the assembly and stops provided as required for operation of hydraulic jacks. An arch or a complete tube can be formed.