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2025 Vol.27, Issue 6 Preview Page

Research Paper

Seismic behavior of buried energy line considering soil-structure interaction

지반-구조물 상호작용을 고려한 매설 에너지라인의 지진 시 동적거동

Chang-Won Kwak1*
곽 창원1*
1Associate Professor, Dept. of Civil and Environmental Engineering, Inha Technical College
1정회원, 인하공업전문대학 건설환경공학과 부교수
*Corresponding Author
30 November 2025. pp. 555-576
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Abstract

Prominent energy lines, such as district heating pipelines, are being designed, constructed, and maintained by 29 district energy operators nationwide, with a total length of 4,720 km × 2 lines (as of 2022). These pipelines supply a massive amount of thermal energy, 39,128 Gcal/h (as of the end of 2021), directly to 3.4 million households in major cities across the country, serving as critical national infrastructure. Following the 2018 Goyang district heating pipeline accident, these pipelines have been recognized as high-risk facilities. Therefore, the safe design, construction, and maintenance of district heating pipelines are directly linked to public safety and convenience. To ensure this, district heating pipelines must be designed based on clear engineering principles. In particular, to ensure safety against the recent surge in medium-sized earthquakes in Korea, seismic design reviews must be conducted in accordance with seismic design regulations (Enforcement Decree of the Act on Countermeasures against Earthquakes and Volcanic Eruptions). However, the seismic design criteria for district heating pipelines have been established without thoroughly considering geotechnical factors such as soil displacement and soil-structure interaction, focusing only on structural engineering aspects like axial strain. This makes the current criteria insufficient for assessing engineering stability, necessitating supplementary research. This study aims to understand the dynamic behavior of district heating pipelines during earthquakes by performing dynamic numerical analysis using the finite difference method. By considering the interaction between the soil and the pipeline structure, we obtain and analyze reliable dynamic behavior, providing a basis for improving the current seismic design criteria that rely solely on longitudinal pipe deformation.

Keywords
Energy pipeline
District heating pipeline
Seismic design
Finite difference method
Dynamic numerical analysis

대표적인 에너지라인인 열수송관은 29개 집단에너지사업자가 전국적으로 설계, 시공 및 유지관리 중이며 총 길이 4,720 km × 2열(2022년 기준)로서 전국 주요 도시에서 총 340만 세대에 39,128 Gcal/h (2021년 말 기준)의 막대한 열에너지를 직접 수요처로 공급하는 주요 국가 기간설비이며 2018년 고양 열수송관 사고를 계기로 고위험 시설물로 인식되고 있다. 따라서 열수송관의 안전한 설계, 시공 및 유지관리는 국민 안전 및 생활 편의성과 직결되며 이를 위하여 열수송관은 명확한 공학적 근거를 바탕으로 설계되어야 한다. 특히 최근 국내에 급증하고 있는 중규모 지진에 대하여 안전성을 확보할 수 있도록 열수송관은 내진설계규정(지진·화산재해대책법)에 의거하여 내진안전성 검토를 수행하여야 한다. 그러나 열수송관의 내진설계 기준은 지반변위, 지반-구조물 상호작용 등 지반공학적 영향인자가 심도있게 고려되지 못한 채 구조공학적 요소인 축방향 변형률만을 검토하여 지진에 대한 안정성 여부를 판단하도록 제정되어 공학적 안정성을 판단하기에 부족한 실정이므로 이에 대한 보완적 연구가 절실히 요구된다. 본 연구에서는 열수송관의 지진 시 동적거동을 파악하기 위하여 유한차분해석법에 의한 동적수치해석을 수행함으로서 지반-열수송관 구조물 상호작용을 고려한 신뢰도 높은 동적 거동을 획득하고 분석함으로서 현재 단순히 종방향 관변형률에 의존하는 내진설계 기준에 대한 개선 근거를 확보하였다.

키워드
에너지라인
열수송관
내진설계
유한차분해석법
동적수치해석
References
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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 : 27
  • No :6
  • Pages :555-576
  • Received Date : 2025-10-13
  • Revised Date : 2025-11-04
  • Accepted Date : 2025-11-05
  • DOI :https://doi.org/10.9711/KTAJ.2025.27.6.555
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