ERIC EJ905108: The Three Gorges Dam of China: Technology to Bridge Two Centuries

4 Pages·2003·0.07 MB·English

by  ERIC

The Three Gorges Dam of China:
18 Technology to Bridge Two Centuries 19
s T
e Wafeek S. Wahby h
di e
u J
gy St Some of the most sophisticated 20th-century cusses the results that are anticipated after its ourn
o a
ol technologies have been applied to build the completion. Some of the challenges faced in l o
chn largest hydroelectric dam in the world, the Three the construction of the project are analyzed, f Te
of Te Gorges Dam Project (TGDP) of China. The together with how they were dealt with. chno
al author administered a study abroad course in lo
Journ Cthhei nmaa fsrsoivme Mpraoyje 2ct7 atso iJt uanpep r1o0a, c2h0e0d0 t,h teo hsatulfdwyay BacTkhger ToGunDdP is projected to become the gy Stu
e d
Th mark of its second and most critical stage, world’s largest dam—nearly four times larger ies
than Hoover Dam, with a height of 607 ft (185
namely Phase II. This article sheds some light
m) and a length of approximately 1.4 miles (2.3
on this sizable project and summarizes informa-
km; Kosowatz, 1999). The TGDP is composed
tion and observations gathered first-hand during
of the dam, two power plants, and the navigation
this study abroad course on the construction of
facilities. The dam is composed of three sec-
the Three Gorges Dam (Wahby, 2000).
tions: the spillway dam, the intake dam, and the
As students, teachers, and other practition- non-overflow dam. The permanent navigation
ers in the various technology professions read structures include a ship lock and a ship lift. A
this article, it is hoped that they may get a better temporary ship lock is also a part of the project
understanding of this substantial project, its that is being used during Phase II of the TGDP.
main components, and the challenges that faced
TGDP Location
and still are facing its construction, as well as
The Three Gorges is one of the world’s
the technologies used to complete it. It is also
most famous scenic sites around Qutang,
hoped that the readers may see the tremendous
Wuxian, and Xiling gorges. The TGDP is locat-
effects of this massive undertaking on different
ed almost 750 miles (1,200 km) south of
aspects, on China as well as on the rest of the
Beijing and 650 miles (1,000 km) west of
world. Those aspects include but are not limited
Shanghai, China. More specifically, the TGDP
to water conservancy, hydroelectric power
is being constructed in Sandouping Village,
generation, environment, ecology, geology,
Yichang County, Hubei Province, in the Xiling
geography, economy, politics, transportation,
Gorge, about 25 miles (40 km) upstream from
society, culture, business, industry, and even
the existing Gezhouba Project located at
technology itself.
Yichang City.
In particular, technology is being challenged
TGDP Site
and stretched to the limit as never before to con-
The site for the TGDP was selected at
struct the Three Gorges Dam. Unprecedented
Sandouping, along the Yangtze River, after
production rates are becoming the norm in order
about 15 other sites were studied. The site has
to keep the sizable project on schedule, while
many advantages. The crystalline rock, intact
adhering to the highest quality requirements of
granite with 100 MPa of compressive strength,
construction codes. After the completion of the
forms a good foundation bed for the dam. In
project by 2009, the technology used in the con-
addition, there are no major unfavorable or inju-
struction of the dam will probably need to be
rious geologic structures in the vicinity of about
reviewed and enhanced in light of lessons
9 miles (15 km) around the dam site, while the
learned.
regional seismic activities are small in intensity,
In addition to a description of the main low in frequency.
components of the project and the phases of its
Interestingly, the river valley at the con-
construction, a historical background and a
struction site of the TGDP is relatively open and
timeline of the events that culminated in China’s
broad, with the hills on both sides of the river
decision to build this dam are presented in this
fairly flat, providing for a good-size lake right at
article. The article also points out the reasons
the upstream of the dam. Also, the existence
why this sizable project is being built and dis-
of the small islet of Zhongbaodao near the right- ground powerhouse with an extra six hydro TGDP Reservoir votes on project (1,700 votes total):
hand side bank of the Yangtze River was turbine generator units totaling 4,200 MW of The TGDP is the largest water conservancy 1,100 for (64%), 400 against (24%),
20 21
favorable for the river diversion project. installed capacity. The intakes of these units are project ever built in the world. The TGDP will 200 abstained (12%).
es being constructed simultaneously with the proj- completely block the Yangtze River course to 1993 Former U.S. and Canadian support Th
di TGDP Main Hydraulic Structures e
u ect. The hydroelectric power generated by the impound a narrow, ribbon-like reservoir. This rib- withdrawn. In their campaigns against J
Technology St 1tsyp.piTlelhw Ttehah ayDet ad6isma0 m-cso,t omthrpyeo hisniegtdah k oedf a dtmharm eise, aas necdcot nitohcnere snt:e ot hnge-roavveitry- Trcaah GvweeDa rcpyPo, aiawmln ocdpuo olrmrdet nbareunewpst tlraiaoobclnleee e4iean0nc eththro gey y5ed 0aeir sv.m ee Tilxlolhppiieomscn tre eetnodltin atosob f lopef,lay bwkwomiidnll)t- —hh o aorlvo fre ni0 vga.e 7etrr o-m lttiahkillae eln,se rnL(ag1atht.kh1ee 0ro Stfkh umoapvn)ee— rari o 4llrea0—sk0se a-mtlhniiadkln eea s,tn wr( e6aisv0ceee0rr vtahogeier t(mghIrReeo nNudtpa,) s mda een,nv dIcen olato uecprromnaagaelteinit otitho,n enaa l nU odRf. S ihUv.u eSamrd seam nNnvi enritiriwsgothnorat-rstkion ournal of Tech
of flow dam. The total length of the dam axis is China’s economy and the prevention of environ- width of the natural river channel. to withhold financial support for the no
al 1.45 miles (2.31 km), with the crest elevation at lo
he Journ 6(11851 f tm ()1, 8655 0m f)t atnhdic ak mata txhiem buamse h, eaingdh t5 0o ff t6 0at7 tfhte mentTaol ppoultl uthtiios ni.n perspective, China’s total milliTonh ek tmot2a. lT whea tseur rcfaactceh amreean to af rtehae irse asberovuot iorne Upanr.oSdj .e sccootc midaupl eai mntoipe isat cse taasg.d e vre rtose b eidnv fioror nthmeental gy Studie
T crest. By comparison, the Hoover Dam in the power capacity in 1990 reached about 130 mil- will reach 1,084 km2, and the land area to be s
1993 First batch of construction teams
United States is 0.24 mile (1,244 ft) long, 727 ft lion kilowatts (Tillou & Honda, 1997). To keep inundated will be 632 km2—almost twice the
enter into the dam site, starting the
high, 660 ft thick at the base, and 45 ft thick at pace with China’s economic growth, with annu- original water surface area. The average annual
construction for the preparatory works
the crest. al increases in the gross national product esti- runoff is 451 billion m3and 526 million tons of
and first-stage diversion works.
mated at 6%, its power output must rise by 8% annual sediment discharge. With the normal
1994 (December 14) Formal start of the
The spillway dam, located in the middle of
annually to reach about 580 million by the year pool level (NPL) at 570 ft (175 m) above sea
TGDP’s construction at the dam site.
the river course, is 0.3 mile (483 m) long in
2015. Given that almost three quarters of level, the total storage capacity of the reservoir
1997 (November 8) End of Phase I,
total, where there are 23 bottom outlets and 22
China’s energy comes from coal, this growing is 39.3 billion m3.
Cofferdam completed, Yangtze River
surface sluice gates. The dimensions of the bot-
coal consumption poses a huge threat to the
diverted, and ships sail through channel,
tom outlets are 23 x 30 ft (7 x 9 m), with the TGDP Dateline
environment. Coal burning emits several harm-
start of second-stage construction.
elevation of the inlets at 300 ft (90 m). The net ful air pollutants, including carbon dioxide Following is the TGDP dateline (Export-
1998 Huge flood caused by the Yangtze River,
width of the surface sluice gates is 27 ft (8 m), (CO)—a major contributor to the greenhouse Import Bank of the United States, 1996):
2 interrupting construction work of the
with its sill elevation at 525 ft (158 m).
effect and global warming. China used between
Three Gorges Dam and affecting 300
1919 Dr. Sun Yat-sen proposes the original
1.1 and 1.2 billion tons of coal in 1993, mostly
On both sides of the spillway dam section flood control dam. million people, with death toll 300,000
for heating and generating electricity. Industry
there are the intake dam and non-overflow dam 1920 Preliminary studies and site people and US$30 billion estimated
sources predict that China will consume as
sections. With a maximum discharge capacity of investigations. losses. This monetary loss of a single
much as 3 to 4 billion tons by the year 2009.
102,500 m3/s - (one m3= 35.32 ft3) at the pool 1954 Huge flood; all transportation stopped flood makes the Chinese government
Sulfur dioxide emissions, which cause acid rain,
level 600 ft (180.4 m), the project is able to dis- for 100 days. even more determined to complete the
are expected to rise from 15.5 million tons in
charge the possible maximum flood (PMF) and 1958 Chairman Mao proposes new plan. project, seeing that its overall cost
1991 to 2.5 billion tons by 2009.
is capable of producing 847 TW.h of electricity 1970 Compromise of the Gezhouba Dam to (US$27 billion) is even less than this
output annually. 3.Navigation Facilities see whether it could be a substitute for single loss.
2000 Phase II underway. Scheduled to be
The permanent navigation structures consist the Three Gorges Dam.
2.Power Stations completed 2003.
of the permanent ship lock and a ship lift. The 1980 Gezhouba Dam completed and proves
Two powerhouses will be placed at the toe 2003 Scheduled end of Phase II and start of
design capacity of annual one-way navigation is not to be a substitute for the TGDP.
of the dam, one to the left and another to the Phase III.
50 million tons. The ship lock is designed as a 1983 Yangtze Valley Planning Commission
right. The total length of the powerhouse on the 2009 Scheduled end of Phase III and comple-
double-way, five-step flight lock carved from completes feasibility study of the Three
left is 0.4 mile (0.65 km), with 14 sets of hydro tion of the TGDP.
granite on the river’s left bank and lined with Gorges Dam.
turbine generator units installed. The total
concrete; each lock chamber is dimensioned at 1985 U.S. working group formed and TGDP Construction Phases
length of the powerhouse on the right is 0.37
930 x 113 x 17 ft (280 x 34 x 5 m)—length x Canadian International Development
mile (0.6 km), with 12 hydro turbine generator The total duration of construction is pro-
width x minimum water depth—capable of lift- Agency finances feasibility study.
units installed. Those 26 sets of hydro turbine jected to be 17 years, divided into three phases:
ing 10,000 tons of barge fleet 285 ft, making it 1989 Canadian International Development
generator units (Francis type, 700 MW each),
the largest such system in the world. Agency (CIDA) determines project is • 1993-1997: First phase construction, including
totaling 18,200 MW of installed capacity, will
technically, environmentally, and
preparation period, dominated
produce 847 TW.h of electricity output annually—
The ship lift is designed as a one-stage ver- economically feasible.
by massive earthmoving. Its
exceeding that of the largest dam currently in
tical hoisting type with a ship container sized 1990 Premier Li Peng revives the project in completion was signaled by the
operation by almost 40%. There are 15 trans-
400 x 60 x 11.7 ft (120 x 18 x 3.5 m), capable the aftermath of Tiananmen Square. damming of the Yangtze River on
mission lines, with 500 kV AC lines to central
of carrying one 3,000 ton passenger or cargo 1991 U.S. Bureau of Reclamation signs con- November 8 and the opening of
China and Chongqing City and about 500 kV
boat each time. In addition, one temporary ship
tract to give technical support. the diversion channel.
DC lines to east China.
lock is designed for use during the construction
1992 End of the 40-plus-year verification
period with an effective chamber size of 800 x • 1998-2003: Second phase construction, will
Meanwhile, enough room has been phase, and the commencement of imple-
80 x 13.3 ft (240 x 24 x 4 m). be completed when the first
preserved on the right bank for a future under- mentation phase. Chinese Congress
generating unit in the left-bank forward. Following is a list of both the advan- 3. The reservoir will flood approximately because heavy sediment buildup in the
power plant goes on line and the tages and disadvantages for the readers to think 75,000 acres of the best agricultural and reservoir is likely to continue to hinder
22 23
permanent ship lock begins and decide for themselves: cultivated farmland in the region, navigation.
es operation. requiring farmers to start cultivating lesser Th
udi TGDP Advantages quality lands. 11. Flood control benefits are overstated; the e J
ogy St • 2003-2009: mThairrkde dp hbays et h(ef icnoaml) pcloentisotrnu ocftion, 1. Falllooowd aC pornectrisoel :cTohnetr oTlG oDvePr itsh ep rYoajnecgttezde to 4. Over 110 sites of cultural and historical roefs tehrev ofliorso dcowualtde rast ebnetsetr isntogr eth oen Ylyan ag tfzraection ourna
Technol atullr b2o6- geelencetrraictoitrys-.producing R90iv%e,r ,t hreedreubcyin sga vthine gs elivfeer iatnyd o pf rfolopoedrtiyn gfr boym importance will be forever lost. during a peak-flow year. l of Tech
of destruction. 5. It is feared that the project will alter the 12. Dam construction will divert funds from no
al TGDP Quantities of Construction Work entire ecological system and adversely more beneficial, less risky projects such as lo
n g
e Jour consTtrhuec tmioani nfo wr oprrkin qcuipaanlt isttireusc ttou rbees daonnde d iinv etrh-e 2. Pato fwuellr cGapeanceirtya,t itohne :TWGiDthP iitss e2s6t itmurabteinde tso aofnfleyc tw tihlel iet novbisrotrnumcte tnhte i nri vtheer’ sa rneaat.u rNalot cYoannsgttrzuec tainndg bsmuialdllienrg s ncaewle cdaanmasls a olor nbgr atnhceh- y Stud
Th sion works are as follows (China Yangtze Three generate 18,200 MW annually, making it course, but it will also inundate hundreds es that may work as safety outlets when the ies
Gorges Dam Project Development Corporation, the biggest hydropower producer in the of acres of land that are the habitat for Yangtze floods attack, which also brings
1999): world. This would provide 15% of China’s many species. water to new areas.
electricity—mostly in the Yangtze River
• Earth-and-rock excavation basin area. That output is equivalent to 6. It is predicted that the devastating environ- 13. The dam would be a military target, creat-
102.83 million m3 approximately 50 million tons of coal or mental damage induced by the project will ing a possible disaster area should it fall
• Earth-and-rock embankment that of 18 nuclear power plants, producing also threaten the river’s wildlife. In addi- due to an attack or due to earthquakes or
31.98 million m3 84 billion kilow.hrs output per year. tion to massive fish species, it will also natural catastrophes.
• Concrete placing 27. 94 million m3 affect endangered species, including the
• Re-bar 463.0 x 103tons 3. Navigation Improvement:The TGDP is Yangtze dolphin, the Chinese sturgeon, the 14. The dam and the reservoir will destroy
• Metal works 256.5 x 103tons projected to allow the passage of 10,000- Chinese tiger, the Chinese alligator, the some of China’s finest scenery and an
• Installation of hydro turbine generator ton ships to Chongqing instead of the Siberian crane, and the giant panda. important source of tourism revenue.
26 sets (18,200 MW) limited 5,000-ton ships, increasing the
TGDP Status Highlights
annual one-way navigation capacity from 7. Chongqing and many other cities along the
TGDP Cost the present 10 million tons to 50 million river will flush tremendous amounts of The second of the three construction phases
of the TGDP is already halfway completed.
In 1990, the cost of the project was estimat- tons, meanwhile decreasing the navigation sewage and toxic waste into the reservoir,
This critical stage presents perhaps the TGDP’s
ed at US$12 billion (Y90.09 billion). A more cost by 35% to 37%. With almost 15 mil- turning it into a “cesspool” that will threat-
biggest challenge: keeping to an aggressively
recent estimate is $27 billion (Y223 billion). lion people, Chongqing will become the en the health of the scores of millions who
ambitious schedule while constructing—accord-
Nearly half of the project’s cost is being applied largest “seaport” in the world. live in the Yangtze basin, while no funds
ing to the highest technical specifications and
to the resettlement of hundreds of villages and have been allocated for water treatment
towns along the river’s edge. If the estimated 4. Other:The project is expected to promote (“China’s Three Gorges Dam,” 1996). foreign inspection—the permanent five-story
cost is increased by a factor of 2.25 within 10 the development of fishery in the reservoir, ship lock, the dam’s spillway, and left intake
years, it might well be possible that the actual as well as tourism and recreational activi- 8. Pollution and slow-moving water could also structure, which will house 14 giant turbines.
cost by the end of the project would reach the ties. To a certain extent, it should improve threaten fish, reptiles, and other wildlife The schedule calls for the first two turbine
$50 billion mark–more than virtually any other the water quality of the middle and lower that depend on the river for their survival. generators to be producing power—and critical
single construction project in history. reaches of the river during the dry season Almost 80 species of fish, Yangtze dolphin, revenue—followed by the remainder of the bank
and create favorable conditions for the finless porpoise, Chinese sturgeon, and in 2003. This means breaking every known
TGDP Controversy south-to-north water transfer projects. giant panda will be endangered (“China’s record for concrete construction (Wahby, 2000).
The construction of China’s Three Gorges Three Gorges Dam,” 1996).
Dam, the largest dam in history, is already in its TGDP Disadvantages To meet deadlines, over 25,000 workers
ninth year and is expected to be completed by 1. The reservoir will flood 13 cities, 140 9. Downstream regions would be deprived of must pour concrete at a pace of about 520,000
2009 with a cost currently estimated at over $27 towns, 1,352 villages, and 657 factories— the fertile silt traditionally carried by the cubic yards (400,000 cubic meters) per month,
billion. Perhaps more than any other project in a great economical, sociological, and cul- Yangtze River as it becomes trapped behind requiring an extensive and complex system for
the history of China, the TGDP has attracted the tural irreversible loss—and will create a the dam. As silt accumulates upstream, it transporting enormous quantities of concrete
attention of many individuals and groups in pollution problem when the infrastructure would affect Chongqing because the water from the mixing plants to the dam. The equip-
China, as well as worldwide, and created much of these communities become submerged level would rise at the reservoir’s opposite ment, from the U.S. supplier Rotec Industries,
controversy, particularly among the experts, due under water. end and submerge parts of it. This also consists of about 5 miles of fast, movable, and
to its almost equally compelling advantages and could cause imbalance in the overburden rotating conveyors.
disadvantages. Supporters of the project believe 2. Construction will force the resettlement of pressure on soil strata, which may increase
that the advantages of the project far outweigh almost two million people, cutting them the risk of earthquakes and landslides, and As the dam progresses to its eventual height
the disadvantages, and, obviously, this is the from their roots and creating all kinds of eventually threaten the dam’s stability. of 607 ft, six tower cranes specially fitted with
social instability associated with a “river jacking systems will raise the conveyors. In
view of the decision makers in the Chinese gov-
refugee new community.” 10. Navigation benefits are exaggerated addition to their lifting capacity, the tower
ernment because the project is indeed moving
cranes have swinging telescopic conveyors that site and Xiling Bridge across the Yangtze No. 1 to 5 powerhouse concrete placement After the completion of the TGDP, precise
are designed to pour concrete at the impressive River have been in operation since October of the basement and the tailrace tube were flood control can be achieved and enormous
24 25
rate of more than 600 cubic yards per hour. A 1996. Main docks and an internal road basically finished. The excavation for No. hydroelectric energy will be produced annually,
es mobile crane delivers concrete from a large system at the site area have been finished. 7 to 14 units was finished by the end of replacing coal consumption and saving the Th
di e
u hauler to construct the dam’s left training wall. 1998. Concrete placement is in progress. environment. However, this will not be without J
Technology St Babmmeeaccotoeaumrunisaetel o’ escfx o schtnerecueardcte titaunesrg aglilyte snshteerotrestan,,t gedlatsahr mag. eHac goveinonnslcguied mt,eh cereausb rcilneang of • Abebxeagcetgacnrvh ecaigontiangnts getp r alpuancrndtoet c pdser ysaossncitdenes mgas ria:nenT gadw bs oylce soa ttngeocmg rsrseue tgpheapatlveye Cbeo tnhWce lhluaersngi eocsont mswpalteetre dc,o nthsee rTvGanDcPy porfo Cjehcitn aas w ill csabuonebssditm d icneeousrng ntsihdnirdagete iarnntiuegnnm gsi onethmrgoe ewu n soie lfcgd iatlthitifieeevs ,eb, n eteoosfwttf eftnocastr s,mm aselnuandcnt hidvo ,ianlsl athgees ournal of Tech
of concrete is essential to keep it at a temperature coarse- and fine-size aggregates for con- well as the largest hydropower station and dam resettlement of almost 2 million people. no
nal of about 45 oF (7 oC) as it hardens. crete mixing. With the addition of two other in the world. Technology is being challenged log
Jour concrete batching plant systems, the con- and stretched to the limit as never before to The TGDP is a massive effort in technology y Stu
e The construction pit for erecting the main crete production rate could reach 2,380 m3 face a variety of engineering challenges in the transfer. The author asked the chair of the d
h ie
T dam was dug to a depth of 260 ft, allowing the per hour, which can satisfy the capability of construction of the TGDP. This includes many Association of Retired Engineers in Chongqing s
foundation work to begin. Numerous holes (with 550 thousand m3per month concrete placing. aspects such as site preparation, the dam’s foun- whether Chinese people are proud of the Great
a total length of more than 60 miles) are currently Each batching plant has its own cooling dations, the details of the project’s main struc- Wall more than they are with the TGDP. After a
being drilled into the ground and filled with pres- system that guarantees a 7 oC temperature tures, some of which are carved in very hard moment of deep thinking, he stated with a smile
surized grout. This “grout curtain” will help pro- for cooling concrete in the summer. rocks, not to mention having to work under that “the Great Wall was built by the Chinese
tect the main dam from uplift by preventing water ever-changing weather. Production rates never people, and it is indeed their pride, but the Three
from seeping underneath the structure. (For the • Diversion works:Completed; diversion before attained are becoming the norm in order Gorges Dam is being built by the whole world,
same purpose, 870,000 sq ft of concrete walls channel opened for navigation on schedule. to keep the sizable project on schedule. After so it should be the pride of the whole world!”
were sunk below the transverse cofferdams.) the completion of the project by 2009, the
• Temporary ship lock project:Completed; technology used in the construction of the dam Wafeek S. Wahby serves as the coordinator
To facilitate transporting thousands of put into operation on schedule. will probably need to be enhanced in light of of the Industrial Technology Program, School of
workers to the construction site, the government lessons learned. Technology, Eastern Illinois University, Charleston.
• Ship lift:Excavation work and concrete
built a four-lane highway from Yichang, the He is a member-at-large of Epsilon Pi Tau.
placement completed on schedule.
nearest city of significant size. By any standard,
the $110-million road, which cuts through the
• Permanent ship lock:The following were References
mountains that frame Xiling, was itself a con-
completed on schedule: Surface and
siderable undertaking: 40% of its total length of China Yangtze Three Gorges Project Development Corporation. (1999, February). Three Gorges
underground excavation, excavation work
17 miles consists of bridges and tunnels, includ- Project.Yichang, Hubei Province, China.
for the lock chambers, concrete placement,
ing a twin bore that is more than 2 miles long. China’s Three Gorges Dam: Is the “progress” worth the ecological risk? (1996, August). Popular
underground excavation of the water feed
Additionally, a 2,950 ft suspension bridge, the Science. Retrieved from http://www.arts.unimelb.edu.au/amu/ucr/student/1996/b.hill/china.htm
and empty system including inclined shafts
longest in Mainland China, outside of Hong Export-Import Bank of the United States. (1996, June 5). Frequently asked questions about the
and gate shafts, concrete lining.
Kong, was built at Sandouping for access to the Three Gorges Dam Project.New York.
project’s right bank.
• Non-overflow dam sections:The concrete Kosowatz, J. J. (1999, December). Mighty monolith. In Scientific American: The big and the small.
placement of the left and right bank non- New York: Engineering News Record.
The double-way, five-step flight ship lock
overflow dam sections was started in 1996 The Three Gorges Dam Corporation. (1997, November 1). Some facts about the Three Gorges
was carved from granite on the river’s left bank
and 1997, respectively. Currently, several Project. Yichang, Hubei Province, China.
and lined with concrete. To carve space for the
segments have reached an elevation of 120
multiple chambers of the lock, workers had to Tillou, S. L., & Honda, Y. (1997). Three Gorges Dam Project, 1997. Retrieved from
m with the left abutment dam sections hav-
blast with precision more than 75 million cubic http://www.american.edu/ted/THREEDAM.htm
ing reached to the crest elevation of 185 m.
yards of hard rock. Wahby, W. S. (2000). China 2000.Report on a study abroad course in China, May 27-June 10, 2000.
Eastern Illinois University, Charleston.
• Left bank intake dam sections and pow-
The construction progress can be described
erhouse:Concrete placement of No. 1 to 6
as follows:
intake dam sections of left bank was started
at the end of 1997. No. 1 to 6 units of the
• Land requisition in dam site:The total
left bank powerhouse are planned to be the
construction area of dam site is 3,700 acres
first batch of generators put into operation.
(15. 28 km2). The land requisition and
Because of its convenient construction con-
relocation of 12 thousand residents have
dition, the excavation of the powerhouse for
been finished and an enclosed manage-
No. 1 to 6 was arranged in the first con-
ment in-site area carried out.
struction stage and was finished at the end
• Internal and outside transportation:The of 1997. The concrete placement was start-
expressway from Yichang city to the dam ed in January 1998. At the end of 1998, the