The use of geosynthetics under freezing temperatures
Location of work/project:
Company:
Summary:
Norway – Tromsø region – Kvitfjell Windpark (Ducatel)
THRACE Nonwovens & Geosynthetics S.A
THRACE geosynthetics were used to stabilize the access road serving for the traffic requirements and to maintain intact the ditches constructed to house the buried cable network of the Kvitfjell Windpark. Despite the challenging engineering conditions (temperatures as low as 28oC), no problems were encountered during the installation process of all geosynthetics.
The area under development is part of the “Norlicht” project, a windmill park on the two neighboring mountains Kvitfjell and Raudfjell, 50 km south-west of Tromsø in North Norway. The wind turbines at Raudfjell and Kvitfjell are collectively one of the major land-based wind power projects in Europe, consisting of 67 wind turbines with a total production capacity of 281.4MW (approximately 200MW in Kvitfjell). The production of the two wind turbines corresponds to the annual power consumption of 50,000 households. Two transformer stations, a switch station, service and storage building, 67 turbine foundations, 33/132kW internal cable network and the upgrade of six kilometers access road from Sørfjorden are some of the components included in the project, which is planned to be completed in the end of 2019.
The combined effect of the local climate conditions (temperatures as low as -28oC), the high-water table (almost surface) and the high traffic loads applied on the access road (47tonnes/turbine + the weight of the vehicle) created challenging engineering conditions in regard the performance of the geosynthetics to be used during both installation and operation.
THRACE Nonwovens & Geosynthetics were used to improve the bearing capacity of the access road foundation.
The TG3030S biaxial extruded geogrid was used to reinforce the 0/45mm base course with a thickness ranging from 250mm up to 350mm. Nonwoven geotextiles, certified as Class N2 and N3 according to NORGEOspecs, were also used to provide the functions of separation and filtration in the structure. The same types of geotextile filters were also used for the construction of the ditches, laterally to the access road, that serve for the buried cable network of the Windpark. It is highlighted that no handling and functional problems were encountered during the installation process of all geosynthetics, even under freezing temperatures (as low as -28oC).