균질지반에서 2단계로 굴착되는 터널의 거동특성에 대한 실험적 연구 = An Experimental Study on the Behaviour of Tunnel Excavated in a Homogeneous Ground by Two-Stage Excavation

국문 초록 (Abstract)

숏크리트 지보 구조는 지반과 숏크리트가 일체화되어 숏크리트 라이닝에 전단력의 전달이 가능한 터널 구조로서 안정한 구조물을 형성하는데 기여한다. 본 연구에서는 석고를 사용하여 일정한 강도를 가진 균질한 모형지반을 제작하였다. 하중재하에 의해 일정한 원지반 응력을 조성한 후 상ㆍ하부반단면 굴착공법으로 굴착하며 굴착시 터널 주변지반의 응력상태와 라이닝의 거동특성을 계측하였다. 측정결과 굴착으로 인하여 터널 주변 지반과 라이닝에 접선방향으로 인창용력이 발생되었다. 단계굴착에 의한 응력 해방율은 상부 경계선 확대천공시 9% 상부반단면 아치부 확대천공시 15%, 상부반단면 경계선 절단 즉시 48%, 안정화 후 하부반단면 굴착전 94%로 나타났다.

다국어 초록 (Multilingual Abstract)

In a shotcrete support system, the cooperation of the ground and the shotcrete lining makes it possible to transfer the shear stress to the shotcrete lining, which is dedicated to form a stable structure. In this study, a homogeneous model ground with constant strength was produced by using gypsum and the tunnel was excavated with a top heading method under the definite initial stress. During the excavation, the stress in the ground around the tunnel and the deformation of shotcrete lining were measured. The tensile stress was generated in tangential direction in the ground near the tunnel and in the shotcrete lining due to tunnel excavation. This shows the unified behavior of the ground and shotcrete lining, which is the most typical characteristic of the shotcrete support. As a result, the rates of in-situ stress during the excavation at a top boundary line was 9"10 and at top arch heading 15%. It was 48% right after excavating the heading and 94% before cutting the bench.

목차 (Table of Contents)

• Abstract
• 초록
• 1. 서론
• 2. 모형시험
• 3. 결과 및 고찰
• 4. 결론
• 참고문헌

참고문헌 (Reference)

1 "안정된 지하구조물의 설계 및 시공." 1994

2 "Single Shell NATM의 설계(Ⅱ)" 4.1 : 72-80, 2002

3 "Single Shell NATM의 설계(Ⅰ)," 4.1 : 73-86, 2002

4 "Simplified Analysis for Tunnel Supports Journal of the Geotechnical Engi- neering Division Proceedings of the American Society of Civil Engineering" 105 : 499-518, 1979

5 "NMT support concepts for tunnels in weak World Tunnel Congress'98 on Metropolises Brazil" 273-279, 1998