YAPI ve MÜHENDİS

Deriner Dam Underground Powerhouse Of Turkey

Deriner Baraji ARTVİN İlinin 5 km membasında Çoruh nehri üzerinde.

Yüksekliği: 247 m
Kret uzunluğu: 720 m
PROJENİN AMACI: Enerji (670 MW, 2118 GWh / yıl )
















Deriner Dam Underground Powerhouse - Turkey
Location: Coruh River, northeast corner of Turkey, 100 km upstream bordering Georgia

The hydroelectric projects on the Coruh River and its tributaries are a vital resource to help increase Turkey's generating capacity and reduce dependence on imported electricity and coal-fired generation.

THE DAM

Highlight: 2nd highest double curvature concrete arch dam in the world
Dimensions: 254-m high
Average flow: 160 m3/sec.

The spill structures consist of orifices through the dam and a concrete chute spillway on the left bank. As the headwaters of the Coruh River flow through soft volcanic rock, and the steep terrain causes many landslides into the river, it is a very muddy river even during relatively low flow. Deriner Dam will create a 70-km long lake that will allow the silt to settle out of the water and thus provide clean water both in the lake and downstream of the dam. This will be a benefit both for recreation and for the fish in the river.

THE POWERHOUSE

Highlight: 5th largest underground powerhouse in the world
Location: 100 m underground
Dimensions: 120 m long x 20 m wide x 45 m high
Instrumentation: Roctest

4 generating units with a total installed capacity of 632 MW operating under a head of 205 m and generating approximately 2100 GWhr/yr.
129 rock anchors of 20 m long and up to 1400 kN in capacity provided support for the walls of the powerhouse during excavation. Support for the ceiling consists of a heavily reinforced cast concrete arch.

INSTRUMENTATION & DATA ACQUISITION

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21 four and five point SAM rod extensometers with vibrating wire sensors for measuring convergence of the ceiling and walls during excavation.
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1 tape extensometer to measure the convergence of the powerhouse walls and ceiling.
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21 oil-filled total pressure cells to measure the stress changes between the native rock and the arched concrete ceiling abutments.
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10 thermometers to measure the cooling rate of the arched concrete ceiling (which was up to 12 m thick at the ceiling abutments).
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10 vibrating wire piezometers to measure water pressure between the concrete lining and the native rock.
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2 Vibrating Wire Load Cells to measure load changes in the rock anchors.
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Senslog 1000X Automatic Data Acquisition System (ADAS) except for temperature guage readings. Five 32-channel multiplexers reduce the amount of cable required.
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A very important aspect of the instrumentation program was reliability. The SAM extensometers installed in the ceiling of the powerhouse would not be accessible after installation due to the depth of excavation (up to 45 m). Thus, they had to operate reliably with no opportunity for servicing for a minimum of three years until the internal concrete structure (walls and floors) was installed in the powerhouse.

Convergence of the powerhouse walls can be clearly seen each time a new bench is excavated in the powerhouse. The convergence movements are primarily measured by the SAM extensometers, and are confirmed by the tape extensometer readings and the increase in the load measured in the rock anchors. The embedded total pressure cells measure stresses between the concrete arch ceiling and the bedrock abutments. Clearly visible is the initial reduction of stress due to shrinkage in the concrete shortly after placement, and then increase in stress due to the deepening of the excavation.

TROUBLE FREE

Roctest provided an engineer on site, full-time, for the duration of the powerhouse instrumentation installation and ADAS commissioning program to ensure that the installations were trouble free and the data collection system would operate reliably for this very important project.

DERINER POWERHOUSE

Rows of rock anchors protruding from concrete blocks are visible on the right and left powerhouse walls. The crew is in a basket suspended from the crane, installing a load cell on a rock anchor 26 meters above the powerhouse floor.