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[VI-931] Efficient bit replacement work of EPB shield tunneling in artificially frozen ground using new soil conditioning material Part 1 Overview of development

〇Yoshio Nishida¹, Hiroyasu Ishii¹, Daichi Kuroiwa², Shigeo Sasahara² (1.Taisei Corporation, 2.Fuji Chemical Co.)

Keywords:Long distance tunneling, Bit replacement, Earth pressure balance (EPB) shield, Artificial ground freezing method, Frozen-resistant conditioning material

Bit exchange is required as the shield tunneling lengthens. At large depths, to ensure bit replacement , a person goes underground using the artificial ground freezing method to perform the replacement work. When the artificial ground freezing method is adopted, the cutter head of the shield machine freezes on the ground, and the cutter head cannot be rotated. Therefore, we developed frozen-resistant conditioning material to prevent freezing of the cutter head and efficiently replace the bit. In this part, we explain the bit replacement work procedure using the freezing method and explain the effects of using frozen-resistant conditioning material.