Abstract
When the structural analysis is performed for the concrete lining of the water pressure tunnel, many parameters are considered such as relaxed ground loads, internal water pressure, external water pressure, the shrinkage of the concrete lining, grouting pressure, etc. But, there are no standards and manuals for the structural analysis for the concrete lining of the water pressure tunnel. Above all, the external water pressure has an much effect on the stability of tunnel. So, in case that permeability of ground is large, the external water pressure should be decreased by installation of weep hole, or reinforced ground by ground improvement grouting should be pressed by the external water pressure instead. But, when weep hole is installed to reduce the external water pressure, the many problems may me occurred. Thus, reasonable approach for treatment of the external water pressure is necessary if weep hole is not installed. Therefore, the purpose of this study is to analyze design cases and studies for treatment of the external water pressure in performing structural analysis for the concrete lining of the water pressure tunnel, and to find reasonable method for tunnel lining modeling which is the treatment of the external water pressure according to permeability of ground and consequently the design of ground improvement grouting.
압력도수터널 콘크리트 라이닝 구조계산시 암반의 이완하중, 내수압, 외수압, 건조수축, 그라우팅압 등 다양한 하중조건을 고려하는데, 아직까지 국내에는 압력도수터널에 대한 콘크리트 라이닝 구조해석을 위한 설계기준 및 체계적인 매뉴얼이 없으므로 설계자에 따라 다르게 적용되고 있는 실정이다. 특히, 도수터널은 외수압을 저감시키기 위해 Weep Hole을 설치하는 경우도 있는데, Weep Hole 설치로 인해 많은 문제점이 야기될 수도 있으므로 Weep Hole을 설치하지 않을 시 외수압 처리에 대한 합리적인 접근 방법이 필요하다. 따라서, 본 논문에서는 압력도수터널 콘크리트 라이닝 구조 계산시 외수압 처리에 대해 기존 설계사례 및 문헌 등을 분석하여 합리적이고 적절한 설계개념에 대하여 서술하였다.