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Project Summary |
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History
The development of Siah Bisheh pumped storage project dates back to
the year 1970 when a study was performed on Hydro electric resources
of Alborz mountain range. The study yielded an inventory of possible
hydropower projects( including pump storage projects) in various
valleys of the northern part of the Alborz mountain range.
In 1975, feasibility studies for three sites (selected from all of
the alternatives) were started. Comparison and evaluation of these
three pumped storage schemes revealed that Siah Bisheh project is
the favorable one. These studies were terminated in late 1977.
In early 1983, a contract for the review of the feasibility study,
the definite design and the preparation of the tender documents was
awarded to a joint venture of international consultants, which was
completed in 1985. From 1985 to 1992 the geotechnical site and
laboratory investigations were continued and the construction design
was completed by the same consultants. Simultaneously, some
preconstruction works such as diversion tunnels, drainage galleries,
access roads and operations complex, as well as excavation of the
power intake and initial portion of the waterway tunnels were
performed. The works were stopped in 1992 for economic reasons.
From 1999 to 2002, a review of the existing design documents was
carried out, and the tender documents were updated, which became the
starting point of the present design and built contract. The present
effort includes a complete review of all previous designs (which is
now completed), suggestion of the required design state-of-the art
modifications (which is mostly completed), and detail design (which
is currently under way). |
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Project Location
| The project is located
in the vicinity of Siah Bisheh village in Mazanderan
province, 125 km to the North of Tehran, and 10 km to the
North of Kandovan Tunnel on the Chalus River. |
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Basic Information
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Client: Iran
Water & Power Resources Development |
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Detail Design:
Kayson-Electrowatt-Ekono |
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Contract Period:
60 months |
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Location: Siah
Bisheh |
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Partners:
Kayson-Beta-Soil Engineering Services (SES) |
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Key Statistics
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Excavation in rocky
ground conditions: 1 million cubic meters |
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Excavation in normal
ground conditions: 3 million cubic meters |
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Earthfill: 4.2
million cubic meters |
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Tunnel excavation:
190,000 cubic meters |
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Shotcrete:
21,000
cubic meters |
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Anchor bars:
250,000 meters |
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Grout holes:
146,000 meters |
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Reinforcement:
22,000 tonnes |
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Formwork, F1 Type:
450,000 square meters |
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Movable formwork:
75,000 square meters |
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Concrete placement:
300,000 cubic meters |
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Objectives
The main objectives of the project can be
summarized as follows:
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To produce up to 1000 MW of
hydroelectricity |
| 2- |
To flatten out variations in the load
on the power grid, permitting thermal power plants that
provide base-load electricity to continue operating at
capacity, while reducing the need to build special power
plants which run only at peak demand. |
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To provide cover for demand surges in
Northern provinces of Iran, thereby stabilizing the entire
North Iran power grid. |
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To reduce maintenance costs of
thermal power plants by as much as 19 million dollars per
year. |
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To provide job
opportunities for local people. |
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Specifications
Upper dam:
Dam type: concrete face rockfill
Height: 82.5 meters
Crest length: 436 meters
Crest width: 12 meters
Foundation width: 280 meters |
Lower dam:
Dam type: concrete face rockfill
dam
Height: 102 m
Crest length: 332 m
Crest width: 12 m
Foundation width: 360 m |
Reservoir:
Volume: 4.3 million cubic meters
Mean annual flow: 9.13 cubic meters per second
Probable Maximum Flood: 200 cubic meters per second |
Reservoir:
Volume: 6.9 million cubic meters
Mean annual flow: 44.4 cubic meters per second
Probable Maximum Flood: 910 cubic meters per second |
Spillway:
Spillway type: free ogee- stepped
spillway
Energy dissipation system: Stilling basin
Location: left abutment
Design flow: 203 cubic meters per second
Chute Length: 490 meters
Chute width : 20 meters
Crest length: 20 meters |
Spillway:
Spillway type: free ogee- stepped spillway
Energy dissipation system: Stilling basin
Location: left abutment
Design flow: 890 cubic meters per second
Chute Length: 200 meters
Chute width : 30 meters
Crest length: 30 meters |
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| Upper Dam Layout |
Lower dam Layout |
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| Diversion
System
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Upper dam
Number of tunnels: 1
Tunnel diameter:
2.95 m
Tunnel length:
570 m |
Lower dam
Number of tunnels: 1
Tunnel diameter:
4 m
Tunnel length:
700 m |
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Headrace
Tunnels
Number of tunnels:
2
Tunnel diameter:
5.7 meters
Tunnel capacity during power generation:
130 m/s (each one)
Tunnel capacity for pumping:
100 m/s
Approximate tunnel length:
2000 m
Number of headrace shafts:
2
Headrace shaft diameter:
5 m
Headrace shaft length:
760 m |
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Geotechnical Aspects of
Upper Dam
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The upper dam is situated in an
asymmetric V-shaped valley of the upper Chalus river. |
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The well exposed rock strata on the
left abutment for the dam spillway, and access road to the
power intake are an asymmetric synclinal structure. |
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The strata are built up by a rock
sequence consisting of siltstone with sandstone and shale
intercalations belonging to Shemshak formation. |
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The drilling results revealed that,
except along faults, a slight weathering occurs on joints,
which are in general iron stained down to a depth of 30 to
40 m. |
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The right abutment is located in a
slided mass called Duna landslide. It is built up by the
disturbed rocks of Shemshak formation and loose materials. |
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The valley bottom in the area of the
dam is covered by river deposits composed of rounded to
sub-rounded cobbles and boulders with subordinately
intercalated gravels, sands and silts. The thickness of the
deposits is approximately 8 to 10 m. |
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| Upper Dam Plan |
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Geotechnical Aspects of Lower
Dam
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The lower dam is situated in a
symmetric V-shaped valley of the lower Chalus River. |
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The dam axis is located about 500
meters down stream of the confluence of Chalus and
Garmrudbar rivers. |
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The foundation area of the dam
consists of well bedded sandstones, limestones, shaly
siltstones and intruded volcanic rocks belonging to the
Dorud formation. |
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Structurally, the ridges forming the
left and right abutments are formed by an anticline with its
axis striking in NW-NE direction. The strata display flat
angles of dip in the central part of the ridges. To the
North, the anticline is followed by a narrow faulted
syncline. To the South, the anticline crest zone (ridges) is
affected by a 5-10 m wide fault zone, forming lateral
gullies on both banks. |
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Two faults cross the plinth and
foundation area on the left abutment. A fault 10-15 m wide,
accompanied by parallel minor faults, will cross the plinth
in the upper reaches of the right bank. |
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Only 30% of the dam area shows
outcropping rock and the remaining part is covered by soil
of different origin and composition. |
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| Lower Dam Plan |
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Seismology
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In the 20th
and 21st centuries, 8
earthquakes happened with magnitudes ranging from 5.2
Richter in Mobarakabad in 1930 to 7.7 Richter in Rudbar-
Manjil in 1990. |
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The latest earthquake was the 6.4 Richter
Firouzabad-Kojour earthquake which shook the western parts
of Mazandaran province on May 28, 2004. |
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Major faults in the region:
The Mosha, Mazandaran-Khazar, North
Tehran, North Ghazvin, Taleghan and North Alborz are the most
important seismic faults which have caused large and destructive
earthquakes in the area. |
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Instrumentation
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Instrument |
Location |
Quantity |
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Hydrostatic Settlement cell |
Right Abutment |
5 |
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Left Abutment |
5 |
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Central Section |
10 |
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Electrical piezometer |
Plinth Foundation |
9 |
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Both Sides of the grout curtain |
4 |
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Dam Foundation along the river bed |
8 |
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Electro level |
Instrumentation Sections |
22 |
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In place inclinometer |
Central Section |
1 |
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Vertical joint meter |
Face Tension Zone |
4 |
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Perimeter joint meter |
Along the Perimeter Joint |
5 |
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Total pressuremeter |
Central Section |
6 |
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Vertical inclinometer |
Dam Axis |
1 |
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Downstream Shell |
1 |
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Cross arm extensometer |
Along the Dam Axis |
3 |
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Cross arm extensometer |
Left Abutment |
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Right Abutment |
2 |
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Central Section |
3 |
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| Project Site
Map |
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