토압식 쉴드 TBM 굴진을 위한 화강풍화토의 컨디셔닝을 평가하는 간편 시험법
A simple test method to evaluate workability of conditioned soil used for EPB Shield TBM
0
조회
0
다운로드
7
인용
0
참고문헌
키워드
초록
토압식(Earth Pressure Balanced, EPB) 쉴드 TBM 굴착에서 첨가제 사용을 통해 막장안정과 배토효율을 증대시키며, 토사지반에의 적용범위를 확대시킬 수 있다. 첨가제로배합된 굴착토사는 배합 전과 그 거동을 달리하는데, 일반적으로 워커빌리티를 평가하여 비교할 수 있다. 본 연구에서는 국내 화강풍화토와 첨가제를 배합한 후 슬럼프 시험을 통해 워커빌리티를 평가하고, 적절한 배합비를 도출하고자 하였는바, 매 경우마다 슬럼프 시험을 실시하는 것이 많은노력을 요하므로 실내 혹은 현장에서 슬럼프 시험보다 간편한 시험법이 필요하다고 판단되어 대체 실험으로서 낙하 콘시험을 고안하였다. 같은 시료에 대하여 슬럼프 시험에 의한 슬럼프 치와 낙하 콘 시험에서의 콘 관입깊이와의 상관관계를 구한 결과 매우 상관성이 높음을 알 수 있었다. 따라서 국내에 편재해있는 화강풍화토에 대한 쏘일 컨디셔닝의 평가에핵심인 슬럼프 치 대신 낙하 콘 시험을 이용할 수 있는 관계식을 제안하였다.
Abstract
Soil conditioning is one of the key factors for successfull tunnel excavations utilizing the earth pressure-balanced (EPB) shield tunnel boring machine (TBM) by increasing the tunnel face stability and extraction efficiency of excavated soils. In this study, conditioning agents are mixed with the weathered granite soils which are abundant in the Korean peninsula and the workability of the resulting mixture is evaluated through the slump tests to derive and propose the most suitable conditioning agent as well as the most appropriate agent mix ratios. However, since it is cumbersome to perform the slump tests all the time either in the laboratory or in-situ, a simpler test may be needed instead of the slump test; the fall cone test was proposed as a substitute. In this paper, the correlation between the slump value obtained from the slump test and the cone penetration depth obtained from the proposed fall cone test was obtained. Test results showed that a very good correlation between two was observed; it means that the simpler fall cone test can be used to assess the suitability of the conditioned soils instead of the more cumbersome slump test.
참고문헌 (11)
- ASTM, "Standard test method for laboratory compaction characteristics of soil using standard effort (12,000 ft-lbf", ft3 (600 kN-m, ASTM International, pp.2012, ~
- ASTM, "Standard test method for slump of hydraulic-cement concrete, C143", C143M-15a, 2015
- British Standard Institution, "BS 1377-2: Soils for civil engineering purposes - part 2: classification", ~ (1990)
- Budach, C., "Untersuchungen zum erweiterten Einsatz von Erddruckschilden in grobkörnigem Lockergestein", Ph.D., pp.2012
- Budach, C., "Application ranges of EPB shields in coarse ground based on laboratory research", Tunnelling and Underground Space Technology, 50, pp.296~304 (2015)
- 김태환, "토압식 쉴드 TBM 굴진을 위한 화강풍화토의 컨디셔닝을 평가하는 간편 시험법", 한국터널지하공간학회 논문집, 20(6), pp.1049~1060 (2018), 사단법인 한국터널지하공간학회[DOI]
- Martinelli, D., "Feasibility study of tar sands conditioning for earth pressure balance tunnelling", Journal of Rock Mechanics and Geotechnical Engineering, 7(6), pp.684~690 (2015)
- Peila, D., "Using the slump test to assess the behavior of conditioned soil for EPB tunneling", Environmental and Engineering Geoscience, 15(3), pp.167~174 (2009)
- Peila, D., "Earth pressure balance tunnelling in rock masses:Laboratory feasibility study of the conditioning process", Tunnelling and Underground Space Technology, 35, pp.55~66 (2013)
- Pena Duarte, M. A., "Foam as a soil conditioner in tunnelling: physical and mechanical properties of conditioned sands", Ph.D., pp.2007
- Quebaud, S., "Use of chemical foam for improvements in drilling by earthpressure balanced shields in granular soils", Tunnelling and Underground Space Technology, 13(2), pp.173~180 (1998)