| 摘要 |
PURPOSE:To make it easy to continuously discharge earth and enable a shield construction method using pressure of mud and earth by using a highly water- absorptive macromolecular water-in-oil type water expansible polymer emulsion as a mud-forming agent, and drilling a hole while supplying the agent to a working face portion. CONSTITUTION:A polyacrylic sodium highly water-absorptive macromolecular water-in-oil type water expansible polymer emulsion is used as a mud-forming agent 101. A cutter head 2 is provided in front of a chamber 3 formed by the partition wall 4 of a tubular steel shell 1 and a center pipe 6 is provided through the cutter 2 and the partition wall 4. An earth discharge pipe 5, feed pipes for the mud-forming agent 101, water 102 and bentnite muddy water 103 are provided behind the center pipe 6. The agent 101, water 102 and bentnite muddy water 103 are properly mixed together and supplied from each feed pipe 7 to a working face portion and the chamber 3. Because the thickening property of the mud-forming agent is high, the state of discharged earth can be bettered. |
