Journal of the Korean Geosynthetics Society (한국지반신소재학회논문집)

Korean Geosynthetics Society (한국지반신소재학회)
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A Pilot Test for the Utilization of Road Subsoil of the Tertiary Mudstone in Pohang Basin

포항분지 제3기 이암의 도로 노체 활용을 위한 현장시험

  • Gong, Jeong-Sik (Dept. of Civil and Environ. Eng., Korea Maritime and Ocean Univ.) ;
  • Baek, In-Woo (Dept. of Civil and Environ. Eng., Korea Maritime and Ocean Univ.) ;
  • Kim, Jae-Gon (Korea Institute of Geoscience and Mineral Resources) ;
  • Song, Young-Suk (Korea Institute of Geoscience and Mineral Resources) ;
  • Kim, Tae-Hyung (Dept. of Civil Eng., Korea Maritime and Ocean Univ.)
  • Received : 2021.06.19
  • Accepted : 2021.09.15
  • Published : 2021.09.30
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Abstract

The purpose of this study is to present the possibility a utilization of the tertiary mudstone in Pohang as road subsoil material through pilot experiments on the road embankment structure. This mudstone is an unconsolidated rock that is distributed in the soft rock sedimentary layer, the tertiary layer of the Cenozoic, and causes physical problems such as slaking, swelling, and reduced shear strength and chemical problem like acid drainage. In order to solve various complex problems, an laboratory mixing test was conducted, and the optimal mixing conditions of the tertiary mudstone (90%), composite slag (steel making 70%, blast furnace 30%), and neutralization and coating agent treatment were derived. In order to prove its utilization, a real-scale road embankment structure was constructed and tests were conducted for each section. The pre-processing section is stable due to the design of optimal mixing conditions, while in post-processing section, natural weathering proceeded rapidly, and structural problems were concerned. Since the effect of neutralizing and coating agents was confirmed in temporary-staking section, the neutralizing and coating agents can be applied during the temporary storage period.

본 연구는 성토구조체 현장실험을 통해 포항 지역의 제3기 이암을 도로 노체 재료로 활용하기 위한 가능성을 검토하는 제시하는 것이다. 이 이암은 신생대 제 3기층인 연암퇴적층에 분포하고 있는 미고결화 암석으로 슬레이킹, 팽윤 현상, 전단강도 저하와 같은 물리적 문제와 산성배수라는 화학적 문제가 발생한다. 여러 복합적 문제 해결하기 위해 실내 배합 시험을 진행하였으며 제 3기 이암(90%)과 복합슬래그(제강 70%, 고로 30%)와 중화·코팅제 처리의 최적 배합 조건을 도출했으며, 이를 실증하기 위해 실제 규모의 도로 성토구조체를 시공하여 구간별 현장 시험을 진행했다. 사전처리구간은 최적 배합 조건 설계로 인해 안정이 유지되는 반면, 무처리구간은 자연 풍화가 빠르게 진행되어 구조적 문제 발생이 우려되었으며, 가적치구간은 중화·코팅제 효과가 확인됨에 따라 임시 적치 시기에 적용 가능함을 확인했다.

Keywords

Acknowledgement

This study is part of the research conducted by the Korea Institute of Geoscience and Mineral Resources, "Reduction of Acid Drainage Damage in Construction Sites and Eco-Resilience Technology Development GP2017-041-2019" and Baek (2020).

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