シールドトンネル(3)

[VI-552] Cases of Overcoming Construction Difficulties in Rock Mass with Lots of Spring Water and High Water Pressure for Shield with Down Gradient

〇Koji Okegawa¹, Nobuo Higuchi², Takuo Katoh¹, Masayuki Fukai², Reo Ozawa², Yoji Takada³ (1.KONOIKE Construction Civil Engineering Department, 2.KONOIKE Construction Tokyo Main Office, 3.City of Sapporo Waterworks Bureau)

Keywords:rock excavation, mud pressure shield method, high water pressure, lots of spring water, fluid transportation

導水トンネルを掘進中に，切羽圧と湧水量が増加したため，泥土圧シールド工法では掘進が困難となった．掘削ずりの排土・運搬方式を泥水式シールド工法で採用される流体輸送方式に変更し，切羽の高水圧・大量湧水地盤の掘進を行った．