1789
Case Studies of Applicability for Selection of Construction Method for Highway
Underground Crossing Transit on the Deposit soils in Urban Project in Korea
Etude de cas du choix de la méthode de construction pour un croisement souterrain d’autoroute sur
sols meubles dans une zone urbaine en Corée
Yang T.-S.
Dept. of Civil Engineering, Kimpo University, Republic of Korea
Yoo N.-J.
Dept. of Civil Engineering, Kangwon University, Republic of Korea
Kim S.-J.
Civil Technology Team, Gyeonggi Innovation Corporation, Gyeonggi Province, Republic of Korea
Hwang Y.-C.
Civil and Environmental Division, Yooshin Engineering Corporaion, Seoul, Republic of Korea
ABSTRACT: Recently various types of underground space have been developed steadily in the urban area; construction of new
underground space interfered often with existing facilities and structures above and under ground, and many difficulties during
construction occurred. In the case of underground works maintaining existing facilities, the design standard for selection of
construction method would be needed to build more economical and rational underground crossing structures by removing the
expected problems in advance. Although many trenchless methods of constructing a highway underground crossing have been
developed and used so far, several difficulties in choosing a proper construction method have been encountered with consideration of
characteristics of each construction method and the site condition. The aim of this paper is to discuss the rational guideline for
selecting an appropriate construction method out of many trenchless methods through a case study in Korea, constructing a road
tunnel under a highway at low depth, accounting for the geological conditions stability during construction.
RÉSUMÉ : Récemment divers types d’espaces souterrains ont été développés intensément dans la zone urbaine ; la construction d’un
nouvel espace souterrain a souvent interféré avec des réseaux existants et des structures au-dessus et au-dessous du sol, engendrant de
nombreuses difficultés pendant la construction. Dans le cas de travaux souterrains conservant les facilités existantes, un processus
normalisé pour le choix de la méthode de construction est nécessaire pour construire plus économiquement et rationnellement des
structures de croisements souterrains en éliminant par avance les problèmes attendus. Bien que de nombreuses méthodes de
construction sans tranchées d’un croisement souterrain d’autoroute aient été développées et utilisées jusqu’ à maintenant, plusieurs
difficultés de choix d’une méthode appropriée de construction ont été rencontrées du fait des caractéristiques de chaque méthode de
construction et des conditions du site. L’objet de cet article est de discuter une procédure rationnelle pour choisir une méthode
appropriée de construction parmi de nombreuses méthodes sans tranchée, à partir d’une étude de cas en Corée, consistant en la
construction d’un tunnel routier au-dessous d’une autoroute, prenant en compte les conditions géologiques et la stabilité pendant la
construction.
KEYWORDS: Design standard, Underground passing, Urban project, Highway crossing
1 INTRODUCTION
NATM (New Austrian Tunneling Method) has been widely
used in Korea for tunnel construction. The main feature of
NATM is to utilize all available means to develop the maximum
self-supporting capacity of the surrounding rock or soil itself,
and to undertake investigation and monitoring during
construction to provide the stability of the tunnel. If undetected
worse ground condition is encountered, the strengthening works
will be carried out to ensure safety. In this case study, the
ground at the entrance of tunnel was revealed to be silty sand
contained a lot of core stones during portal excavation, not just
as the weathered and soft rocks as originally predicted before
design. Thus the tunnel face collapsed with water spouting, and
the upper ground surface was also sunk at the same time. The
remediation measures including ground grouting, tunnel
reinforcing and invert lining were then implemented and
completed successfully(H
an
, 2012).
Recently many problems in the geotechnical engineering
aspect have been raised as various kinds of underground space
have been developed steadily in the urban area. In particular,
for underground space in urban area, construction of new
underground space interfered often with existing facilities and
structures above and under a ground and many difficulties
during construction occurred. In the case of building road or
railway under a ground, maintaining operation of existing
facilities, the design standard for selection of construction
method would be needed to build more economical and rational
underground crossing structures by removing the expected
problems in advance of construction works.
Although many trenchless methods of constructing a highway
underground crossing have been developed and used so far,
several difficulties in choosing a proper construction method
have been encountered with consideration of characteristics of
construction methods and the site conditions. This paper is to
discuss the rational guideline for selecting an appropriate
construction method out of many trenchless methods through
the case study of Gwanggyo Project known as the typical
example of urban project in Korea, designing and constructing
the road tunnel under the highway on the deposit soil at a
relatively low depth of underground. Considering geological
condition, stability during construction, and economic
efficiency, the trenchless method applied to this project is
selected and discussed in this paper.
