SHIELD EXCAVATION METHOD BY USING BUBBLE AND JELLY

PURPOSE:To improve the permeability to a facing by using a silicic acid type paste obtained by crushing a silicic acid type water jelly having a specific wt.% of including rate of silicon dioxide, and bubbles or a foaming agent, as a pouring material of a shield excavation method. CONSTITUTION:A shield type excavator 1 under the ground, and a pouring material feeding plant 2 on the ground are connected to a pouring line 3 through a compression pump 4, and a feeding port 8 of the pouring material is provided on the face plate 7 having the facing cutter 6 of the shield type excavator 1. Then, an earth pressure chamber 9 is provided at the near side of the facing cutter 7, a ribbon screw 10 is provided linking to the earth pressure chamber 9, a sand plug zone 12 is formed at the rear side, and the excavation muck mixed with the pouring material is filled in the earth pressure chamber 9. Then, minute particles produced by crushing a silicic acid type water jelly having about 1 to 60wt.% of including rate of silicon dioxide; a silicic acid type paste mainly of a liquid having a liquidity provided among the minute particles; and bubbles or a foaming agent; are used as a pouring material. And such a pouring material is delivered and poured to the facing through the pouring line 3.