Constructing the Kdrahnjukar Face Slab Karahnjukar Hydroelectric Project-Iceland
The Kárahnjukar hydroelectric project is located 20 km north of the Vatnajokul glacier on the vast and uninhabited plateau in eastern Iceland. The principal structure of the project is the 198m high concrete faced rock filled Kdrahnjukar dam which is located asymmetrically in a dramatic narrow deep canyon. The dam face slab is supported in the canyon on a toe wall while the right abutment plinth is anchored on to the steep core of the extinct Kdrahnjukar volcano and the left plinth is supported by a shallower glacial abutment. Safely constructing the face slab of such a structure would be a major undertaking under normal circumstances,however doing so under the prevailing extreme climatic arctic conditions proved to be exceptionally challenging.In addition this endeavour was further complicated since the design and construction sequence of the face slab had to be revised a number of times in view of the uncovered geological conditions and the concurrent experiences of other similar dams under construction and impoundment in South America. The purpose of this paper is to give a brief account of the particular features and problems that were encountered,and the measures that were adopted to successfully construct the subject face slab,without delaying impoundment. The concreting of the slab concrete is discussed,while emphasis is placed on the variety of winterization measures that were implemented to overcome the severe climatic conditions. The paper also refers to the major changes that were introduced into the design concept of the central canyon portion of the face slab. The experience of Kdrahnjukar has shown that it is possible,if not recommended,to successfully and safely construct large face slabs during long winters,where the normal prevailing conditions are of extended periods of darkness,low temperatures,icycold winds and snow storms with speeds a-bove 170 km per hour. This was achieved by the close cooperation,prompt and flexible measures that the Owner,Designer and Contractor adopted to help mitigate the effects of unexpected occurrences. The ability and willingness to radically re-schedule activities and redistribute resources,is one of the most important options that the involved parties have to limiting the effect of negative impacts on a project.Finally,the experience has confirmed that there is no substitute for dedicated personnel,safety awareness,detailed planning,organization and logistics.
face slab eztreme climate winterization
Gianni Porta Richard Graham
Impregilo S.p.a.Via Dei Missaglia 97,20142 Milano,Italy
国际会议
The 1st International Symposium on Rockfill Dams(第一届堆石坝国际研讨会)
成都
英文
463-470
2009-10-18（万方平台首次上网日期，不代表论文的发表时间）