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2025 Vol.41, Issue 4 Preview Page
Physical Characterization of Tunnel Backfill Materials under Mixing Conditions

터널 뒤채움 재료의 배합 조건에 따른 물리적 특성 분석

Tae-Young Kim1
,
Hee-Hwan Ryu2
,
Seon-Ah Jo3
,
Haejin Lee4
,
Song-Hun Chong5*
김 태영1
,
류 희환2
,
조 선아3
,
이 해진4
,
정 성훈5*
1Member, Ph. D. Student, Dept. of Civil Engineering, Sunchon National Univ.
2Member, Principal Researcher, Power System Research Laboratory, KEPRI
3Senior Researcher, Power System Research Laboratory, KEPRI
4Researcher Associate, Power System Research Laboratory, KEPRI
5Member, Prof., Dept. of Civil Engineering, Sunchon National Univ.
1정회원, 국립순천대학교 토목공학과 박사과정
2정회원, 한국전력연구원 전력계통연구소 책임연구원
3비회원, 한국전력연구원 전력계통연구소 선임연구원
4비회원, 한국전력연구원 전력계통연구소 위촉연구원
5정회원, 국립순천대학교 토목공학과 교수
*Corresponding Author
31 August 2025. pp. 41-51
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Abstract

In the shield TBM method, filling the tail void with backfill grout is critical to ensuring the long-term stability of the tunnel and preventing ground settlement. However, no defined standards exist for quantitatively evaluating the engineering performance of backfill materials, such as their flowability and strength. Existing test methods are typically designed for cement mixtures with very low w/c ratios and therefore do not adequately account for the chemical characteristics involved in practice (e.g., hardening agents, mixing time, and the order of additive incorporation). This study quantitatively investigates the engineering properties of field-applied two-component backfill grout as a function of cement type, w/c, and hardener-to-water ratio (H/W), under mixing sequences and stirring durations designed to reflect their chemical properties. In particular, this study presents foundational data for optimal mix design by deriving the relationship between flowability and compressive strength, thereby ensuring adequate workability while satisfying the required strength.

Keywords
Hardener-water ratio
Mixing method
Tail void
Two-component backfill grout

쉴드 TBM 공법에서 테일보이드(tail void) 내 뒤채움재의 충전은 터널의 장기적 안정성과 지반 침하 방지를 위한 핵심 요소이다. 그러나 현재까지 뒤채움재의 유동성과 강도 등 공학적 성능을 정량적으로 평가할 수 있는 명확한 기준은 미흡한 실정이다. 기존 시험 방법은 주로 매우 낮은 w/c 조건의 시멘트 혼합 재료에 한정되고 실제 시공에서 사용되는 화학적 특성(예: 경화제 조성, 교반 시간, 첨가제 투입 순서 등)을 충분히 반영하지 못하고 있다. 이에 본 연구는 실제 현장에서 사용되는 이액형 뒤채움재를 대상으로, 재료의 화학적 특성을 고려한 혼합 순서 및 교반 시간 조건 하에 시멘트 종류, 물-시멘트비(w/c), 경화제-물비(H/W)에 따른 재료별 공학적 특성을 정량적으로 비교하였다. 특히 유동성과 압축강도 간의 상관관계를 도출함으로써, 일정 수준 이상의 유동성을 확보하면서도 요구 강도를 만족시키는 최적 배합 설계를 위한 기초자료를 제시하였다.

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Information
  • Publisher :The Korean Geotechnical Society
  • Publisher(Ko) :한국지반공학회
  • Journal Title :Journal of the Korean Geotechnical Society
  • Journal Title(Ko) :한국지반공학회 논문집
  • Volume : 41
  • No :4
  • Pages :41-51
  • Received Date : 2025-06-10
  • Revised Date : 2025-07-08
  • Accepted Date : 2025-07-27
  • DOI :https://doi.org/10.7843/kgs.2025.41.4.41
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