1699
Proceedings of the 18
th
International Conference on Soil Mechanics and Geotechnical Engineering, Paris 2013
Construction of a Cross Passage between Two MRT Tunnels
Construction d’un passage entre deux tunnels de MRT
Y. S. Fang, C. T. Lin & C. Liu
Department of Civil Engineering, National Chiao Tung University, Hsinchu, Taiwan
K. H. Cheng
Department of Rapid Transit Systems, Taipei City Government, Taipei, Taiwan
C. S. Su & T. J. Chen
Railway Department II, Sinotech Engineering Consultants, Ltd., Taipei, Taiwan
ABSTRACT: This paper reports the ground improvement and excavation of a cross passage between two shield tunnels for the
construction of Tu-chen Line of Taipei Rapid Transit Systems. Jet grouting was conducted for soils around the cross passage before
the tunneling with the shield machine. Water-leak tests were conducted to detect any possible crack in the JSG soilcrete, and chemical
grouting was conducted from the shield tunnel to fill any possible crack. It is concluded that the subsurface conditions encountered at
great depths might be quite complicated. The geotechnical engineer should never overestimate the watertight characteristics of the
soilcrete formed around the cross passage by jet grouting and chemical grouting. Under the threat of high water pressure, the
contractor is suggested to bear the multiple-defense-lines concept to keep the excavation work on the safe side.
RÉSUMÉ : Cet article rapporte la amélioration de terrain et la excavation d’un passage au travers entre deux tunnels bouclier pour la
construction de la Ligne Tu-chen des Systèmes de Transit Rapide de Taipei. La injection a été conduit aux sols autour de la passage
au travers avant la machine bouclier à percer. Les essais de fuite d’eau sont été conduit à détecter un éventuel fissure dans la
béton-sols de JSG, et la injection chimique a été conduit aux les fissures rimplies a partir de tunnel bouclier. Il est conclut que les
conditions de surterrain rencontrées dans les différentes profondeurs peut-être assez compliquées. L’ingénieur de géotéchnique devrait
jamais suréstimer les caractéristiques de étanchéité de béton-sols formés autour de la passage au travers par la injection chimique.
Sous la menace de haut pression d’eau, l’entrepreneur est suggéré de s’apporter le concept de multiple-défense-lignes à garder le
travail d’excavation dans un bon côté.
KEYWORDS: cross passage; jet grouting; ground improvement; tunnel; water leak test.
1 INTRODUCTION
The mass rapid transit (MRT) system is one of the most
efficient transportation methods in metropolitan areas.
However, the densely-populated traffic movements are
restricted in a small and close environment. In case of an
emergency, such as a fire in an underground tunnel, it might be
very difficult for the passengers to evacuate and could easily
cause exceedingly heavy casualties and loss of lives.
The National Fire Protection Association (NFPA) required
that, to minimize the damage, cross passages between the MRT
main tunnels should be constructed for safety and evacuation
Cross
passage
Ground
improvement
zone
Surface
settlement
marker
To Far Eastern
Hospital Station
MRT UT
tunnel
Nan Ya S. Rd.
MRT DT
tunnel
To Fuzhong
Station
North tunnel of
Taiwan Railway
South tunnel of
Taiwan Railway
TC-B01
SB-16
Figure 1. Location of MRT tunnels and cross passage.
reasons. In the design and construction of Taipei MRT,
Kaohsiung MRT and Taoyuan International Airport MRT in
Taiwan, a cross passage must be fabricated for every 250 to 500
m of single-circular double-tube tunnels.
It should be noted that the excavation of an underground
cross passage is a highly risky operation and many associated
accidents were reported in the literature. Under the threat of
high water and earth pressure, an opening have to be cut on the
steel lining segment of the completed main tunnel. The
excavation of the cross passage was carried out under the
indefinite protection of the improved ground, steel supports and
assembled steel segments. In case of an accident during the
excavation of the cross passage, the groundwater and soils
might flow into the excavation zone, causing large amounts of
ground loss, and induce excessive ground movements which
might damage the completed main tunnels. In this paper, the
ground improvement and construction of the cross passage for
lot CD266 of Taipei MRT is introduced.
2 GROUND IMPROVEMENT FOR CROSS PASSAGE
2.1
Project description
Construction lot CD266 of the Tu-chen Line of Taipei MRT
included the Far Eastern Hospital station, Fuzhong station, and
two sections of shield tunnels. In Figure 1, the cross passage
between two MRT tunnels is located on the Nan Ya South
Road, in the south-west of the lacustrine Taipei basin. Based on
the data from boring SB-16 (Sinotech Engineering Consultants,
Construction of a Cross Passage between Two MRT Tunnels
Construction d’un passage entre deux tunnels de MRT
Fang Y.S., Lin C.T., Liu C.
Department of Civil Engineering, National Chiao Tung University, Hsinchu, Taiwan
Cheng K.H.
Department of Rapid Transit Systems, Taipei City Government, Taipei, Taiwan
Su C.S., Chen T.J.
Railway Department II, Sinotech Engineering Consultants, Ltd., Taipei, Taiwan
