Geology Reference
In-Depth Information
Engineering Contract (ICE, 2005) states that in judging the physical
conditions, the contractor is assumed to have taken into account:
-
The site information
-
Publically available information referred to in the site information
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Information available from a visual inspection of the site , and
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Other information that an experienced contractor could reasonably
be expected to have or to obtain.]
7.4.4 Geological structure: Ping Lin Tunnel,
Taiwan
The Ping Lin Tunnel in Taiwan (now called the Hsuehshan Tunnel) was
eventually completed after numerous delays, collapses and deaths. The
plan was to excavate a pilot tunnel using a 4.8m diameter rock TBM
followed by two 11.74m diameter TBMs for the main tunnels, but the
anticipated tunnelling rates of up to 360m/month/machine proved
hopelessly optimistic because of adverse ground conditions. The geol-
ogy included a syncline of sandstone with several faults. The pilot
tunnel TBM soon ran into trouble as slow seepage from a fault drain-
ing the saturated aquifer above rapidly increased and
ooded the
tunnel (Figure 7.11 ). Attempts were made to construct bypass tunnels
and to advance each of the TBMs using pre-grouting to improve the
rock mass, but much of the tunnelling had to be done using drill and
blast methods rather than using the purpose-built TBMs. Details of
this project are described by Barla & Pelizza (2000).
7.4.5 Deep weathering and cavern inll: Tung
Chung, Hong Kong
The new town at Tung Chung is situated close to Hong Kong
International Airport and for a large part was built on offshore
Figure 7.11 River
of water out of pilot
tunnel TBM, Ping
Lin, Taiwan.
 
 
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