Relocation of Penstock Route and Detailed Design of Köklüce HEPP – Turkey

Project Name: Relocation of Penstock Route and Detailed Design of Köklüce HEPP

Country: TURKEY

Client: Palet Construction Co

Finance Source: DSI (State Hydraulic Works)

Tags: Turkey, Local, HEPP, Design

Narrative Description of Project:

In this project, water is diverted from YeÅŸilırmak River by Ataköy Dam and conveyed to Köklüce HEPP situated at Kelkit River Valley by means of a 6 530 m long power tunnel with an inner diameter of 3.80 m and a 2 000 m long penstock with an inner diameter varying between 3.20 m and 2.10 m. By utilizing 437 m gross head between these two valleys, an energy production of 584 million kWh per year will be realized at Köklüce HEPP, which has an installed capacity of 2×45 MW.

Köklüce penstock route passes 1.5 km south of North – Anatolian Fault that is the most active fault zone of Turkey. Main geological formations along the penstock route lying between power tunnel outlet and Köklüce HEPP are volcanic tuff – breccia – algomera, schistose claystone – sandstone, clay, slope wash and ophiolitic series.

In March 1983, an extensive landslide has occurred and caused severe destructions on the concrete substructures along the penstock route so that there was no possibility for the erection of penstock over the surface any more. Therefore as an alternative solution, penstock was first embedded in a concrete lined shaft of 120 m height and then passed through a 400 m long tunnel and 180 m long conduit (open tunnel) below the sliding area. In addition a counter weight fill composed of granular material was foreseen over the conduit for long term stability of the sliding mass.

Description of Actual Services provided by TEMELSU:

Alternative solutions for relocation of the penstock were analysed and detail designs for the new route and the necessary structures were carried out. Also, during the construction, consultancy services have been provided for the client.