TUNNEL EXCAVATION METHOD AND TUNNEL EXCAVATOR

摘要

PROBLEM TO BE SOLVED: To make it possible to flow spring water to the outside even in case unexpected volumes of spring water occurs and to prolong the life of fluid pressure packing provided in the circumference of an excavator main body for stopping the spring water. SOLUTION: The water level in a hopper 60 is controlled in the specific level by controlling an amount of water supply by water supply pump with the water level in the hopper 60 or controlling discharge with suction pump. When the water level in the hopper 60 is abnormally raised, the discharge from the suction pump is increased, or an amount of water supply from the water supply pump is decreased or eliminated. A fluid pressure packing 33 for stopping spring water from a cutting face 38 is provided. When the water level in a chamber 2 is abnormally raised, the higher water level, the higher fluid pressure supplied into the fluid pressure packing 33 obtains.