Journal of Korean Tunnelling and Underground Space Association (한국터널지하공간학회 논문집)

Korean Tunnelling and Underground Space Association (한국터널지하공간학회)
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A study on the correlation between the rock mass permeability before and after grouting & injection volume and the parameters of Q system in a jointed rock mass tunnel

절리 암반터널 내 그라우팅 전·후의 암반 투수계수 및 그라우팅 주입량과 Q 시스템 항목들과의 상관관계 연구

  • Received : 2012.11.01
  • Accepted : 2012.11.19
  • Published : 2012.11.30
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Abstract

In this study, correlations between the rock mass permeability before and after grouting & injection volume and the parameters of Q system were investigated on a grouted rock mass tunnel corresponding to rock class 4 and 5 in terms of Q classification system. As a result, it appears that the lower the Q value is, the higher the before-grouting permeability becomes and the smaller the injection volume of grouting becomes. Also RQD and Jn are the most influencing factors to the permeability of rock mass and the injection volume of grouting. In addition, it turned out that it was very difficult to lower the permeability of rock mass smaller than $1.0{\times}10^{-8}$ m/sec with the ordinary portland cement grout.

본 연구에서는 그라우팅이 실시된 4~5 등급(Q 분류의 1 이하)에 해당 되는 암반 터널을 대상으로, 그라우팅 전 후의 암반 투수계수 및 그라우팅 주입량과 Q분류법의 파라미터들간의 상관관계를 분석해 보았다. 연구 대상 터널의 경우 Q 값이 작을수록 그라우팅 전 암반 투수계수는 커지며, 그라우트의 주입량은 작아지는 것으로 나타났다. 또한 투수계수 및 주입량에 가장 큰 영향을 미치는 요인은 RQD 및 절리군수(Jn)인 것으로 나타났다. 또한 보통시멘트를 주입재로 한 암반터널 그라우팅 작업에서 투수계수를 $1.0{\times}10^{-8}$ m/sec이하로 낮추는 것은 매우 어려운 것으로 나타났다.

Keywords

References

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  1. Probabilistic rock mass classification using electrical resistivity - Theoretical approach of relationship between RMR and electrical resistivity- vol.15, pp.2, 2013, https://doi.org/10.9711/KTAJ.2013.15.2.097