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2016 Vol.18, Issue 2 Preview Page
Assessment of elastic-wave propagation characteristics in grouting-improved rock mass around subsea tunnels

해저터널 주변 그라우팅 보강암반의 탄성파 전달특성 평가

Ji-Won Kim1
,
Eun-Soo Hong2
,
Gye-Chun Cho3*
김 지원1
,
홍 은수2
,
조 계춘3*
1KAIST, Dept. of Civil and Environmental Engineering, Ph.D. Candidate
2KAIST, Dept. of Civil and Environmental Engineering, Research Associate Professor
3KAIST, Dept. of Civil and Environmental Engineering, Professor
1카이스트 건설 및 환경공학과 박사과정
2카이스트 건설 및 환경공학과 연구부교수
3카이스트 건설 및 환경공학과 교수
*교신저자. *Corresponding Author. 
31 March 2016. pp. 235-244
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Abstract

Grouting is frequently used before the construction of subsea tunnels to mitigate problems that can occur in weak ground zones such as joints, faults or unconsolidated settlements during construction. The grout material injected into rock mass often flows through the discontinuities present in the host rock and hence, joint properties such as its distribution, roughness and thickness greatly affect the properties of grouting-improved rocks. The grouting-improved zones near subsea tunnels are also subjected to high water pressures that can cause long-term weathering in the form of changes in grout microstructure and crack formation and lead to subsequent changes in ground properties. Therefore, an assessment method is needed to accurately measure changes in the grouting-improved zones near subsea tunnels. In this study, the elastic wave propagation characteristics in grouting-improved rocks were tested for various axial stress levels, curing time, joint roughness and thickness conditions under laboratory conditions and the results were compared with wave velocity standards in different Korean rock mass classification systems to provide a basis for inferring improvement in grouted rock-mass.

Keywords
Grout
Rock grouting
Elastic wave surveying
Subsea tunnel

해저터널 시공 중 단층, 파쇄대 및 미고결층 등의 취약한 지반조건에서 일어나는 문제점을 극복하기 위해 시공 중 그라우팅을 진행한다. 암반에서 그라우팅은 주로 불연속면을 따라 주입되므로 절리의 분포, 거칠기 또는 폭과 같은 절리 인자들이 그라우팅 보강암반의 물성에 지대한 영향을 미친다. 해저터널 주변의 그라우팅 보강암반은 해저환경에서 정수압을 다 부담하여 장기적인 열화와 미세구조변화 및 균열 등이 발생하며 암반물성이 시간에 따라 변하므로 그라우팅으로 인한 해저터널 주변암반의 장기적인 거동평가가 요구된다. 본 연구에서는 실내실험을 통해 다양한 축 응력, 양생기간 및 절리조건에서 그라우팅 보강암반의 탄성파 전달특성을 분석하였고 국내에서 사용되는 다양한 암반분류법들의 탄성파 기준을 고려하여 그라우팅 보강암반의 보강정도를 탄성파 속도로 추론하였다.

키워드
그라우트
암반 그라우팅
탄성파 탐사
해저터널
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Information
  • Publisher :Korean Tunneling and Underground Space Association
  • Publisher(Ko) :한국터널지하공간학회
  • Journal Title :Journal of Korean Tunnelling and Underground Space Association
  • Journal Title(Ko) :한국터널지하공간학회 논문집
  • Volume : 18
  • No :2
  • Pages :235-244
  • Received Date : 2016-03-10
  • Revised Date : 2016-03-21
  • Accepted Date : 2016-03-22
  • DOI :https://doi.org/10.9711/KTAJ.2016.18.2.235
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