Design of temporary bypass tunnels in a long high-speed railway tunnel and an efficient assessment of intersection stability

Heesuk Lee; Jaewook Lee; Taesik Jeon; Euijoon Hong; Youngjin Kim; Soonkyo Hong

doi:10.9711/KTAJ.2026.28.2.083

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2026 Vol.28, Issue 2 Next Page

Technical Paper

Design of temporary bypass tunnels in a long high-speed railway tunnel and an efficient assessment of intersection stability 장대 고속철도 터널의 임시 우회터널 설계 및 효율적인 교차부 안정성 평가

31 March 2026. pp. 83-105

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Abstract

To meet the stringent construction deadlines of long-distance tunnels, simultaneous operations across multiple working faces are essential, requiring the strategic integration of temporary access tunnels. In this project, it was identified that the initial access plan was insufficient to guarantee timely completion. Consequently, additional temporary bypass tunnels were designed to expedite the schedule. Given that construction was already in progress, the objective was to develop a reliable design methodology within a limited timeframe by maximizing the utility of existing design data. The primary focus was placed on the structural stability of tunnel intersections. To optimize the time-intensive process of complex 3D numerical analysis, rapid stability assessments were executed by leveraging historical 3D intersection data and utilizing 3D Boundary Element Method (BEM) analysis. The results were further validated through stability evaluations for each support pattern based on the critical strain approach. Finally, an efficient restoration plan for the temporary tunnels was proposed to minimize environmental impact and ensure post-construction sustainability.

Keywords

Long tunnel

Tunnel design

Schedule shortening

Temporary bypass tunnel

Intersection stability

장대 터널 공사에서 예정된 공기를 준수하기 위해서는 복수의 막장을 동시에 굴착하는 다점 분할 시공이 필수적이며, 이는 각 작업면과 연결된 임시 사갱(Access Tunnel)의 건설을 동반한다. 본 프로젝트에서는 기존에 계획된 사갱만으로는 공기 준수가 어렵다고 판단되어, 시공 속도 향상을 위한 추가 임시 우회터널(Bypass Tunnel)을 설계하였다. 시공이 이미 진행 중인 상황임을 고려하여, 기존 설계 데이터를 최대한 활용함으로써 단기간 내에 신뢰성 있는 설계 방법론을 수립하는 것을 목적으로 하였다. 특히 터널 교차부의 구조적 안정성 확보를 최우선 과제로 삼았다. 복잡하고 시간이 많이 소요되는 3차원 수치해석 과정을 최적화하기 위해, 기존의 교차부 설계 데이터와 3차원 경계요소해석(BEM)을 병용하여 신속한 안정성 검토를 수행하였다. 분석 결과의 타당성을 검증하기 위해 한계 변형률(Critical Strain) 접근법을 적용하여 각 지보 패턴별 안정성을 평가하였으며, 공사 완료 후 환경 영향을 최소화하기 위한 효율적인 임시 터널 복구 방안을 제안하였다.

키워드

장대터널

터널 설계

공기단축

임시 우회터널

교차부 안정성

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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 : 28
No :2
Pages :83-105
Received Date : 2026-01-29
Revised Date : 2026-03-09
Accepted Date : 2026-03-09
DOI :https://doi.org/10.9711/KTAJ.2026.28.2.083

Journal of Korean Tunnelling and Underground Space Association ISSN:2233-8292(Print) 2287-4747(Online) 한국터널지하공간학회 논문집

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