Abstract:

A remotecontrolled device that can conveniently regulate the diameter of the cutting installations is proposed in order to improve the adaptability of soft ground shield machines to the specific works and the geological conditions. The design of the telescopic scrapers, the design of the wear limit monitoring devices and the operation of the diametervarying cutting installations are presented and analyzed. The proposed remotecontrolled diameter varying method has such advantages as shorter construction time, higher safety and lower cost. The proposed method can be used in cases where it is hard to replace the scrapers or where measures should be taken to prevent the boring diameter becoming less than the shield diameter after the cutterhead has been seriously worn. The proposed method can be serviced as a special design requirement of shield machines, especially when the shield machines are boring under water or when there is no chance to suspend the boring to replace the scrapers.

Key words: soft ground, shield machine, diameter varying, cutting, control, regulation