Prediction of long-term tunnel behavior using a ground strength degradation model

Jungkuk Kim; Heesu Kim; Sangyun Kim; Byounghun Kim; Hoki Ban

doi:10.9711/KTAJ.2025.27.4.317

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2025 Vol.27, Issue 4 Preview Page

Research Paper

Prediction of long-term tunnel behavior using a ground strength degradation model 지반 강도저하 모델을 이용한 터널장기거동 예측

31 July 2025. pp. 317-329

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Abstract

Tunnels play a critical role in improving transportation and logistics by enabling the efficient use of underground space. However, as tunnel operation periods are prolonged, the surrounding ground undergoes degradation, resulting in cumulative deformation of the tunnel subgrade and potential impacts on structural stability. This study aims to evaluate the long-term behavior of tunnel structures by conducting a numerical analysis of subgrade heaving over a 30-year service period, using a ground strength degradation model. The material property changes corresponding to 10~70% ground degradation were derived based on degradation coefficients proposed in previous studies. In this study, these coefficients were continuously applied over time to quantitatively assess the subgrade uplift behavior. The numerical analysis was performed using the commercial finite element program ABAQUS. The results showed that after 30 years, the vertical displacement reached 43.13 mm without an invert, whereas it was reduced to 3.98 mm with an invert, confirming over 90% reduction in deformation. These findings indicate that the installation of an invert is advantageous for maintaining long-term tunnel stability, even under severe ground degradation conditions.

Keywords

Ground degradation

Strength degradation model

Long-term behavior

Tunnel subgrade uplift

Numerical analysis

터널은 지하 공간의 효율적 활용을 통해 교통 및 물류 흐름을 개선하는 핵심 인프라이다. 그러나 운영 기간이 장기화됨에 따라 주변 지반의 열화로 인해 터널 노반의 수직변위가 발생하고, 이는 구조적 안정성에 영향을 미친다. 본 연구는 터널 구조물의 장기 안정성 확보를 목적으로, 지반 강도저하 모델을 기반으로 터널 공용기간인 30년 동안 노반의 수직변위를 확인하고자 수치해석을 수행하였다. 지반 열화율 10~70%에 따른 물성치 변화는 선행연구를 통해 도출된 모델 계수를 적용하였다. 이를 바탕으로 본 연구에서는 이를 시간 경과에 따라 연속적으로 적용하여 노반의 수직변위 및 터널 주변 지반의 소성변형을 정량적으로 분석하였다. 해석은 상용 유한요소 해석 프로그램인 ABAQUS를 이용하여 터널공용기간인 30년으로 수치해석을 수행하였으며, 30년 후 수직 변위는 인버트 미설치 시 43.13 mm, 설치 시 3.98 mm로 약 90% 이상의 저감 효과가 확인되었다. 이를 통해 열화율이 높은 조건에서도 인버트가 장기 안정성 확보에 유리한 것으로 나타났다.

키워드

지반열화

강도저하모델

장기거동

터널 노반 융기

수치해석

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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 :4
Pages :317-329
Received Date : 2025-07-18
Revised Date : 2025-07-22
Accepted Date : 2025-07-22
DOI :https://doi.org/10.9711/KTAJ.2025.27.4.317

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

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