SYNTHETIC GEOMEMBRANES ENHAMCE SAFETY IN DAMS
Safety of a dam during its entire life is related to a variety of factors including characteristics of foundations，seismic events， climate，construction materials and procedures， thermal behaviour(thermal cracking in RCC dams)， uplift(efficiency of drains)，swelling processes(AAR)，etc.The entity and influence of these factors cannot always be predicted with accuracy,and can have negative effects on the safety of the dam.The use of geomembranes can improve safety because their characteristics are engineered，constant and controlled with standard methods，granting constant quality.Imperviousness of a geomembrane system can be engineered to sustain events that would cause failure of other waterproofing systems，and is not dependent on weather conditions at placement.Geomembranes have tensile characteristics that can accept large settlements and differential movements even in presence of seismic events.In RCC dams， adopting a geomembrane allows using a low cementitious content mix，minimising the concern for thermal cracking，and providing safe performance even in case cracks develop during operation.In RCC dams with high cementitious content，geomembranes are used as external waterstops， designed to accommodate movements between blocks much larger than any.foreseen possible movement.An upstream drained geomembrane system，by intercepting and removing at the upstream face seeping water，and water already saturating the dam，allows reducing the design uplift in RCC dams，controlling the uplift in ageing dams，and reducing the swelling process in dams subject to AAR.The paper discusses how geomembranes can be useful in improving safety, with some significant case histories.
Geomembrane geocomposite drainage
Alberto SCUERO Gabriella VASCHETTI Yao ZHANG
Carpi Tech S.A.，Chiasso，Switzerland Beijing Biwing High-Tech Co.，Ltd
国际会议
High-level International Forum on Water Resources and Hydropower(第一届国际水利水电高层论坛)
北京
英文
389-403
2008-10-17（万方平台首次上网日期，不代表论文的发表时间）