Spoil removal from tunneling face is assisted by adding viscosity-raising agent to face water entering screw outloading conveyor.

摘要

Spoil is loaded out from the tunnel face by face water make diluted with viscosity-raising agent using a screw conveyor to flush the spoil and water out from the face area. Raising the viscosity brakes down the water movement through the screw and so enables the flowing water to collect all spoil grades and fines and prevent screw blockages. Suggested agents include clay, straw, woodwool, shaving etc as available.