By putting most of its
new high-speed railroad on viaducts, Taiwan is avoiding many
construction pitfalls along the route through the urbanized
corridor that stretches across the islands western coast.
Production line techniques for thousands of 800-tonne girders
further eliminated snagsbut not SARS and seismic events
that harried the $15-billion, three-year-old construction project.
Engineering aftershocks of the
1999 "Chi-Chi" earthquake that devastated central
Taiwan first hindered progress. Then, as resulting seismic
design uncertainties were being resolved last year, the disease
SARS afflicted the island, spurring a mass exodus of migrant
TRAINS High-speed rail line stretches 345 km.
(Photo courtesy of Taiwan High-Speed Rail Corporation)
Dave Herron, project manager of
a consortium responsible for 37 kilometers of the high-speed
line near Taichung, says that his team is now finishing up,
having recently ended work ahead of schedule. Other joint
ventures along the route are also completing the nearly 350-km
of infrastructure. With civil work now ending, "progress
has been tremendous," says Nita Ing, chairwoman and chief
executive officer of the Taiwan High-Speed Railway Corp. As
mechanized track installation gains momentum. equipping and
commissioning railroad systems this year and next remain "a
very big challenge," she adds.
With most of its population concentrated
along the coast between Taipei and Kaoshiung, Taiwan seems
well-suited for high-speed trains. When completed in late
2005, the line will shuttle trains at 300 km per hour along
a continuous stretch of development between the islands
north and south extremities.
Conceived in the 1980s, the project
took off as a 35-year build-operate-transfer contract awarded
to THSRC in 1997. Among THSRCs five core members is
Continental Engineering Corp., Taipei, Taiwans largest
From Ground Up
Starting "from zero," THSRC created a company in
the first six months after winning its contract and built
on that over two years, says Continental Engineering executive
Chao-Yi Chia. "At the very beginning, some people thought
it was Mission Impossible," he says.
THSRC secured initial financing
in early 2000 and awarded 12 civil contracts, together worth
some $6 billion. THSRC chose fixed-price, lump-sum, design-build
contracts for better efficiency, says S.C. Lin, the companys
assistant vice president for civil construction management.
Traditionally, design was done "very conservatively and
very expensively," he explains.
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Only the lines stations are
being built according to the owners designs. Here, THSRC
eschewed design-build to control the architecture, says T.C.
Kao, vice president for buildings. Work on six new stations
and two upgrades, costing $600 million, began in May 2002.
They are due to open in October 2005, with another four after
For the civil work, all 12 consortiums
are dominated by Asian contractors. Germanys Bilfinger
+ Berger Bau AG and Hochtief AG are among the few non-regional
major firms, providing experience that even the largest local
firms lacked, says Cheng-Hsiung Kang, a senior executive of
Tunneling on the rail line usually encountered
sands and clays. (Photo courtesy of Taiwan
High-Speed Rail Corporation)
Continental is Bilfinger + Bergers
equal partner in the projects BBCE joint venture, which
has two adjacent contracts near Taichung covering 80 km and
worth about $1.1 billion. The team has built 66 km of viaduct,
and drove the 7.4-km-long Paghuashan tunnel.
BBCE this January handed over its
last section to the tracklayers some two months ahead of schedule,
says former project co-director Stefan Roth. That, however,
was a deadline extended early on to accommodate a lengthy
engineering debate triggered by the 1999 Richter 7.3 Chi-Chi
earthquake, which killed some 2,000 people.
Stunned by that devastation, the interior ministry altered
earthquake zoning and changed seismic design criteria for
all public works, says THSRCs Lin. "We sent a letter
to all contractors...that was really a shocksome had
already started design [and] the [original] code was already
conservative." BBCEs design had reached an advanced
stage, says Roth. "That was destroyed by the new earthquake
zoning," he says.
The new seismic criteria, which
varied depending on ground conditions, were extremely complicated,
says Herron, BBCE project manager on one contract for 24 km
of viaduct and seven tunnels. One example of the seismic changes
was a 25% increase in skin friction safety factoring for piles
Adding up the cost of all proposed
changes along the route resulted in a potentially ruinous
30 to 40% cost hike, says Lin. But a subsequent review rescued
the project. Essentially, it found the original criteria to
be adequate. But by September 2000, when the government reverted
to them, "we had wasted about five months," he says.
BBCE and the owner agreed on acceleration
measures and payments, but not on the effect on quantities
used or their costs, says Roth. The whole earthquake review
"influenced our design approach," he says. "What
is being provided is on the [conservative] side." Herron
adds that BBCE and the owner have reached accord on all payments.
Acknowledging the effect on schedules,
THSRC issued time extensions. Herrons contract received
an extra two months and more resources, including a third
precast concrete production line at the site.
Steelwork launchers placed
800-tonne girders for much of the rail viaduct.
(Photo courtesy of Taiwan High-Speed
Of the roughly 345-km railroad, nearly 40 km is tunneled,
while over 250 km is on viaducts and bridges that avoid disrupting
highways and communities. For most of the viaducts, "you
had a choice...of using full span precast concrete or casting
on a normal shoring system," says Herron. "Segmental
construction was not allowed for high-speed rail."
Because the southern section needed
to be completed earlier for train tests, its contractors opted
for conventional cast-in-place decks on traveling formwork,
says Lin. Some 10% of other viaducts were cast on props. Balanced
cantilever, deck launching and steelwork bridges were used
over sites such as rivers.
Nearly two-thirds of the viaduct
was built with full-span precast box girders, adds Lin. Steelwork
launchers advancing onto waiting piers place the 800-tonne
girders. One of five contractors used its launcher to deliver
girders, while the others moved them on wheeled vehicles.
BBCE is now trying to sell its three 40-wheel, 200-tonne transporters.
BBCEs choice of full span
precasting "meant we could concentrate our resources
in one area and limit the work being done in the-right-of
way primarily to substructure,"says Herron. "And
it reduces the work force."
Designed by a team of Bilfinger
engineers in Germany and U.K.-based FaberMaunsell Ltd., BBCEs
section of viaduct typically comprises post-tensioned girders
up to 35 m long, 6 m wide and more than 3 m deep with 13-m-wide
top slabs. The supporting piers vary in thickness and are
generally 6 m tall.
BBCEs two contracts started
in April 2001 with foundation work. Pad foundations occur
mainly in the rocky northern region. Sands and clays in a
high water table further south are more prone to liquefaction
in earthquakes, requiring piles.
Working in gravel with cobbles
in places, the contractor used hydraulic rigs to drive 2,400
partially cased piles, with excavations supported by polymer
fluid. In easier sands and clays, a fleet of reverse circulation
rigs drove some 5,000 piles. Generally, viaduct piers are
supported by four 2-m-dia piles some 60 m deep.
Pier work followed closely behind
piling, and BBCE crews cast and placed the first of nearly
700 whole-span girders in October 2001 after six months setting
up the three production lines. The yards gantry cranes
placed the first girder. Later, spans were erected with a
single advancing launcher until last August.
Apart from a minor collapse, tunneling
on BBCEs stretch of railroad was uneventful, Herron
says. The twin-track tunnels typically have horseshoe-shaped
profiles with 130-sq-m excavated faces. They were excavated
and temporarily supported with arches and spray concrete,
followed by cast-in-place reinforced lining.
At the 7.4-km Paghuashan tunnel,
Herrons team excavated four faces through variable clay
and sand. They achieved an average of 6.5 m per day, peaking
at 14.2 m, says tunnel manager Frank Hemmert. "The original
design showed a lot of rock bolts. We found they were not
needed," he says. With the ground almost self-supporting,
"we redesigned everything."
In contrast, the 4.3-km Hukou tunnel,
about 70 km from Taipei, has collapsed twice. The tunnel is
part of a design-build contract for 18.4 km of line, held
by a joint venture led by Daiho Corp., Tokyo, with Taiwanese
firms Chiu Tai General Contractor Co. Ltd. and Kou Kai Construction
Trouble started after the heading
had broken through between two faces near the north portal
in August 2002, says THSRCs Lin. After the 50-m obstruction
was excavated that October, a 250-m-long collapse occurred
near the tunnels mid-point. "We cant identify
the cause," says Lin. But "we knew this was the
most difficult tunnel" due to the wet, weak sands.
Slow and Deliberate
VIADUCTS Viaducts built by launching of precast
girders aimed to minimize disruption to local communities
and wildlife. (Photo courtesy of Taiwan High-Speed Rail
While such construction snags have been rare, bureaucracy
has been rampant. For the 12 engineering teams, waiting for
their designs to be checked and ensuring uniformity has been
"a tedious process," says Herron. "In the early
stages, when everybody was getting to grips with the design
criteria...there were times we thought it would be impossible."
For each contract, there is an
independent team checking all plans in detail. A higher-level
team, reporting to the owner, audits the process by reviewing
sample designs. If all goes well, the client issues a "statement
of no objection," allowing construction to proceed. But
the process was so slow that the "final statement of
no objection was achieved after all the spans were installed,"
Worried about delays, BBCEs
team and other consortiums short-circuited the checking system.
"The penalties on the project are so high that you cannot
be late. And the indications were [that] you would not get
extensions of time due to the approvals process," says
Herron. So rather than wait for the owners green light,
BBCE kept building on the basis of its detailed checkers
"The risk was...to build something
that could have ended in a big dispute," says Roth. But
"we always worked on the safe side" and never as
far as the critical design, adds his co-director, Cheng-Hsiung
Kang. There was not any construction on BBCEs contracts
that needed retrofitting or remediation, says Herron.
THSRCs Lin agrees that the
approval process was "too complicated," blaming
it on the BOT procurement method. But "its still
much faster than if wed been working for a government
agency,"notes Roth. "The push is there....They wanted
The checking woes diminished over
time, but then SARS erupted, terrifying the Thai workers that
account for most of BBCEs payroll. "We lost about
20% of our workers," says Herron. Many declined to renew
their visas and went home to avoid exposure to SARS.
A strict disinfecting regimen and
twice-a-day health checks seemed to reassure many workers.
"You had to have full monitoring in place to make sure
you didnt get SARS. That would have been a catastrophe.
We would have been shut down," says Herron. By increasing
the number of subcontractors and raising overtime, "we
just had to manage."
Nevertheless, construction dust
is now finally settling. "We never expected that we could
complete [the project] so soon," reflects a relieved
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