درباره ماتماس با ماتلکسموبایلRSSستاد خبري مركز حراست وزارت نيرو
جمعه 10 مرداد 1393
Publish Date: 1391/01/09 10:36 ق.ظ
Transfer of Koohrang Valley water to Zayandehrood Valley (Koohrang 3 Tunnel)
The project is designed to transfer 300 million cubic meters of water per annum in order to partly make up for drinking, industrial and irrigation water shortage in central Iran and to boost the volume of the regulated water of the Zayandehrood River through Koohrang 3 reservoir dam.
مازندران_

Studies 

In light of the fact that the Zayandehrood River has been a major contributor to growth in central Iran, development of the river has been on the mind of officials for centuries.
Under Shah Abbas I, efforts were made on orders of Sheikh Bahaei to build a canal to transfer the water of Koohrang to Zayandehrood. During the reign of Shah Abbas II a French engineer Dnchenai tried to use gunpowder to dig a similar tunnel. His efforts remained inconclusive.
Eventually, Sir Alexander Gibb and his colleagues carried out the Koohrang Dam and Diversion Tunnel 1 project which was inaugurated in 1953.
The average volume of water transferred through this tunnel annually stood at 300 million cubic meters.
Sugra Consultant Engineers took care of the studies and design of a second tunnel as well as Marbaran Tunnel. Construction work on the tunnels got underway in 1972 and the project came on stream in 1985. The tunnels transfer some 250 million cubic meters of water each year. 

In the same year as the inauguration of the second tunnel, studies were launched by Zayandrood Consulting Engineers for a third tunnel. Strovi Export, a firm from the former Czechoslovakia offered geophysical services and Geotechnika, a former Yugoslavian company, rendered geotechnical services along the process. After two rounds of studies, a tender was invited in 1991. One year later, Tabliyeh Company was chosen as the contractor of the project and construction work got underway in September 1994. Complementary studies on phase two of the project were conducted by Mahab Qods Zayandehab Company in 1999 and concluded in 2002.

Intake coordinates: 50-18 eastern, 32-15 northern
Outlet coordinates: 50-15 eastern, 32-19 northern
The mouth of intake tunnel is 2,200 meters above sea level.
The mouth of outlet tunnel is 2,182 meters above sea level.
Length of tunnel: 23,049 meters
Diameter of tunnel excavation: 4.9 to 5.4 meters (circular and U-shaped)
Final diameter of tunnel: 4 to 4.1 meters (circular)
Slope of tunnel: 0.000742 and 0.00131
Tunnel hydraulic regime: Under pressure
Flow control location: Tunnel outlet
Maximum transferable discharge: 44.5 cubic meters per second
Intake structure: Concrete trash collector and stop plug (4 by 4)
Location of intake shaft: 0+750 kilometer; 40 meters in height; wheeled cut-off gate with fixed axis measuring 3.2 by 3.1 meters
Outlet control system: Y-shaped with two sectoral gates each measuring 2.5 by 2.4 meters
Type of coating: Armed concrete between 0.35 and 0.5 meters in thickness and special flexible coating at the site of active faults
Total volume of excavation: 490,000 cubic meters
Total volume of concrete used: 180,000 cubic meters
Number of access tunnels: 4
Length of access tunnels: 3,745 meters 


Geology of tunnel 

Stratigraphically speaking, the tunnel is located in the High Zagros zone and passes through the following:
Green lake marls, red Miocene marls, Cretaceous lime, Triassic dolomite, Jurassic lime, lower Cretaceous lime (K1), middle Cretaceous lime (K2), upper Cretaceous marls, Pliocene conglomerates, thick and thin Eocene limes (E1 to E5), and Cenozoic silts.
The tunnel lies on four major fault lines namely Shahryari, Zarab, Lagharak and Na'l Ashkan.

1. Outlet access tunnel 

This structure is designed to open new operational fronts, and speed up operations and ventilation.
It is located at Kilometer 22+329 of the entrance and is 165.1 meters in length.
The excavation site is a right-angle U and 4.5 meters in diameter.
Negative slope: 10%

2. Na'l Ashkan access tunnel 

This structure is also designed to open new operational fronts, and speed up operations and ventilation.
It is located at Kilometer 17+118.7 of the entrance and is 679.8 meters in length.
The excavation site is a right-angle U and 5 meters in diameter.
Negative slope: 14%

3. Nasirabad 2 access tunnel 

This structure is designed to open new operational fronts, and speed up operations and ventilation. It is also meant to help excavate part of the tunnel which passes through Na'l Ashkan Fault and lime zones. Besides, it is used to retrieve the tunnel boring machine (TBM).
It is located at Kilometer 11+600 of the entrance and is 1,399 meters in length.
The excavation site is a right-angle U and 5.5 meters in diameter.
Negative slope: 14.3%

4. Nasirabad 1 access tunnel 

This structure is designed to open new operational fronts, shorten the critical route of the project and facilitate ventilation. Besides, it is used to bring out the tunnel boring machine (TBM).
It is located at Kilometer 9+538.2 of the entrance and is 1,500.8 meters in length.
The excavation site is a right-angle U and 5.5 meters in diameter.
Negative slope: 13.5%

Hydrogeology of tunnel 

Considering the fact that there are huge lime deposits and major fault lines along the route of the tunnel, huge discharge is predicted in the following:
- Between kilometers 1+600 and 3+150 where there is a high concentration of hydrated lime. (Head static stands at 9 p)
- At the site of Zarab fault line between kilometers 3+150 and 3+550 where a hydrated fault zone is seen.
- Where the middle Cretaceous lime deposits meet the Na'l Ashkan fault line. In this area two different types of marls cross paths at kilometer 11+400. At this area Nasirabad access tunnel hit huge caves. Consequently there was a huge discharge. After the water was pumped out and injection, water tightening, stabilization, and lining operations were completed, operational activities resumed.
- At thick Eocene limes. As predicted in the studies there was a large discharge (15 p) at an area 109 meters in length. More excavation and injection were required before the premiere of the tunnel could be stabilized.
- Water is expected to gush at kilometer 15+800 where there are thick Eocene lime deposits.

Protection 

The primary protection along the route of the tunnel usually comes in the form of mesh wire and shotcrete. Whenever needed tensioned and untensioned rock bolts are also used.
In places where deposits are shattered and fault lines exist and at the entrance of the tunnel (red and green marls as long as 1,600 meters) metal casing is used along with mesh wire and shotcrete to protect the tunnel. Final protection comes in the form of concrete.

Overall specifications 

Studies are underway for construction of Koohrang 3 Dam in order to contain runoff water, increase the volume of regulated water and divert flash floods along the Koohrang River.
Type of Dam: Concrete
Height: 2,235 meters above sea level
Height of riverbed: 2,153 meters above sea level
Height of crest: 2,240 meters above sea level
Width of crest: 4 meters
Length of crest: 341 meters
Total volume of reservoir: 412 million cubic meters
Useful volume of reservoir: 361 million cubic meters
Volume of regulated water: 233 million cubic meters 

Implementation 

Excavation from the entrance portal through kilometer 1+600 which contains red and green marls takes place by means of a T 1-30 tunnel boring machine at upper and lower levels. Between kilometers 1+600 and 3+150 before the route crosses Zarab fault line explosives are used and devices such as jumbo-drill and hog loader are employed.
On the Nasirabad front as far as the lime rock spreads explosives are used for excavation. Then a new S 125 model of Open TBM is used in excavations. Still then at the site of Zarab fault line explosives are used.
On Nasirabad front, explosives are used on the intake and outlet fronts.
On Na'l Ashkan front, explosives are used on the intake and outlet fronts; from kilometer 1+600 toward the entrance an old Open TBM is used.
On the outlet front explosives are used for 1,600 meters and the remaining 4,100 meters is excavated by means of the old Open TBM.
Application of sophisticated machinery such as telescopic frames as long as 24 meters, re-mixers and snorkels has sped up concreting.

 


Studies 

In light of the fact that the Zayandehrood River has been a major contributor to growth in central Iran, development of the river has been on the mind of officials for centuries.
Under Shah Abbas I, efforts were made on orders of Sheikh Bahaei to build a canal to transfer the water of Koohrang to Zayandehrood. During the reign of Shah Abbas II a French engineer Dnchenai tried to use gunpowder to dig a similar tunnel. His efforts remained inconclusive.
Eventually, Sir Alexander Gibb and his colleagues carried out the Koohrang Dam and Diversion Tunnel 1 project which was inaugurated in 1953.
The average volume of water transferred through this tunnel annually stood at 300 million cubic meters.
Sugra Consultant Engineers took care of the studies and design of a second tunnel as well as Marbaran Tunnel. Construction work on the tunnels got underway in 1972 and the project came on stream in 1985. The tunnels transfer some 250 million cubic meters of water each year. 

In the same year as the inauguration of the second tunnel, studies were launched by Zayandrood Consulting Engineers for a third tunnel. Strovi Export, a firm from the former Czechoslovakia offered geophysical services and Geotechnika, a former Yugoslavian company, rendered geotechnical services along the process. After two rounds of studies, a tender was invited in 1991. One year later, Tabliyeh Company was chosen as the contractor of the project and construction work got underway in September 1994. Complementary studies on phase two of the project were conducted by Mahab Qods Zayandehab Company in 1999 and concluded in 2002.

Intake coordinates: 50-18 eastern, 32-15 northern
Outlet coordinates: 50-15 eastern, 32-19 northern
The mouth of intake tunnel is 2,200 meters above sea level.
The mouth of outlet tunnel is 2,182 meters above sea level.
Length of tunnel: 23,049 meters
Diameter of tunnel excavation: 4.9 to 5.4 meters (circular and U-shaped)
Final diameter of tunnel: 4 to 4.1 meters (circular)
Slope of tunnel: 0.000742 and 0.00131
Tunnel hydraulic regime: Under pressure
Flow control location: Tunnel outlet
Maximum transferable discharge: 44.5 cubic meters per second
Intake structure: Concrete trash collector and stop plug (4 by 4)
Location of intake shaft: 0+750 kilometer; 40 meters in height; wheeled cut-off gate with fixed axis measuring 3.2 by 3.1 meters
Outlet control system: Y-shaped with two sectoral gates each measuring 2.5 by 2.4 meters
Type of coating: Armed concrete between 0.35 and 0.5 meters in thickness and special flexible coating at the site of active faults
Total volume of excavation: 490,000 cubic meters
Total volume of concrete used: 180,000 cubic meters
Number of access tunnels: 4
Length of access tunnels: 3,745 meters 


Geology of tunnel 

Stratigraphically speaking, the tunnel is located in the High Zagros zone and passes through the following:
Green lake marls, red Miocene marls, Cretaceous lime, Triassic dolomite, Jurassic lime, lower Cretaceous lime (K1), middle Cretaceous lime (K2), upper Cretaceous marls, Pliocene conglomerates, thick and thin Eocene limes (E1 to E5), and Cenozoic silts.
The tunnel lies on four major fault lines namely Shahryari, Zarab, Lagharak and Na'l Ashkan.

1. Outlet access tunnel 

This structure is designed to open new operational fronts, and speed up operations and ventilation.
It is located at Kilometer 22+329 of the entrance and is 165.1 meters in length.
The excavation site is a right-angle U and 4.5 meters in diameter.
Negative slope: 10%

2. Na'l Ashkan access tunnel 

This structure is also designed to open new operational fronts, and speed up operations and ventilation.
It is located at Kilometer 17+118.7 of the entrance and is 679.8 meters in length.
The excavation site is a right-angle U and 5 meters in diameter.
Negative slope: 14%

3. Nasirabad 2 access tunnel 

This structure is designed to open new operational fronts, and speed up operations and ventilation. It is also meant to help excavate part of the tunnel which passes through Na'l Ashkan Fault and lime zones. Besides, it is used to retrieve the tunnel boring machine (TBM).
It is located at Kilometer 11+600 of the entrance and is 1,399 meters in length.
The excavation site is a right-angle U and 5.5 meters in diameter.
Negative slope: 14.3%

4. Nasirabad 1 access tunnel 

This structure is designed to open new operational fronts, shorten the critical route of the project and facilitate ventilation. Besides, it is used to bring out the tunnel boring machine (TBM).
It is located at Kilometer 9+538.2 of the entrance and is 1,500.8 meters in length.
The excavation site is a right-angle U and 5.5 meters in diameter.
Negative slope: 13.5%

Hydrogeology of tunnel 

Considering the fact that there are huge lime deposits and major fault lines along the route of the tunnel, huge discharge is predicted in the following:
- Between kilometers 1+600 and 3+150 where there is a high concentration of hydrated lime. (Head static stands at 9 p)
- At the site of Zarab fault line between kilometers 3+150 and 3+550 where a hydrated fault zone is seen.
- Where the middle Cretaceous lime deposits meet the Na'l Ashkan fault line. In this area two different types of marls cross paths at kilometer 11+400. At this area Nasirabad access tunnel hit huge caves. Consequently there was a huge discharge. After the water was pumped out and injection, water tightening, stabilization, and lining operations were completed, operational activities resumed.
- At thick Eocene limes. As predicted in the studies there was a large discharge (15 p) at an area 109 meters in length. More excavation and injection were required before the premiere of the tunnel could be stabilized.
- Water is expected to gush at kilometer 15+800 where there are thick Eocene lime deposits.

Protection 

The primary protection along the route of the tunnel usually comes in the form of mesh wire and shotcrete. Whenever needed tensioned and untensioned rock bolts are also used.
In places where deposits are shattered and fault lines exist and at the entrance of the tunnel (red and green marls as long as 1,600 meters) metal casing is used along with mesh wire and shotcrete to protect the tunnel. Final protection comes in the form of concrete.

Overall specifications 

Studies are underway for construction of Koohrang 3 Dam in order to contain runoff water, increase the volume of regulated water and divert flash floods along the Koohrang River.
Type of Dam: Concrete
Height: 2,235 meters above sea level
Height of riverbed: 2,153 meters above sea level
Height of crest: 2,240 meters above sea level
Width of crest: 4 meters
Length of crest: 341 meters
Total volume of reservoir: 412 million cubic meters
Useful volume of reservoir: 361 million cubic meters
Volume of regulated water: 233 million cubic meters 

Implementation 

Excavation from the entrance portal through kilometer 1+600 which contains red and green marls takes place by means of a T 1-30 tunnel boring machine at upper and lower levels. Between kilometers 1+600 and 3+150 before the route crosses Zarab fault line explosives are used and devices such as jumbo-drill and hog loader are employed.
On the Nasirabad front as far as the lime rock spreads explosives are used for excavation. Then a new S 125 model of Open TBM is used in excavations. Still then at the site of Zarab fault line explosives are used.
On Nasirabad front, explosives are used on the intake and outlet fronts.
On Na'l Ashkan front, explosives are used on the intake and outlet fronts; from kilometer 1+600 toward the entrance an old Open TBM is used.
On the outlet front explosives are used for 1,600 meters and the remaining 4,100 meters is excavated by means of the old Open TBM.
Application of sophisticated machinery such as telescopic frames as long as 24 meters, re-mixers and snorkels has sped up concreting.