The addition material and its production manner, and the tunnel construction method null sodium silicate which are used for shield tunneling method

摘要

An additive material for use in the shielding method or pipe-jacking method in the tunneling of a water-bearing sand gravel layer or sand layer. The additive material eliminates problems concerning the corrosion of apparatuses, etc. caused by the liquid properties of raw materials for the additive material and by liquid properties of the additive material produced. The additive material can be easily produced in a short time and can form a modified soil having high homogeneity. The additive material for use in the shielding method or pipe-jacking method is characterized by being a siliceous paste obtained by mixing sodium silicate, a bicarbonate, and water to obtain an aqueous siliceous gel and pulverizing the gel to form a sol. The additive material for use in the shielding method or pipe-jacking method may be characterized by being a siliceous paste obtained by mixing sodium silicate, a bicarbonate, a polymeric coagulant, and water to obtain an aqueous siliceous gel and pulverizing the gel to form a sol.