Naslov
Impact of a grout curtain on groundwater regime in karst: the example of the Ðale reservoir (Croatia)

Autori
Bonacci, Ognjen ; Roje-Bonacci, Tanja

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
EGU General Assembly 2010 ; Geophysical Research Abstracts Vol. 12, / - Beč : European Geosciences Union (EGU), 2010, 1366-1366

Skup
EGU General Assembly 2010

Mjesto i datum
Beč, Austrija, 03.05.2010. - 07.05.2010

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
grout curtain; groundwater; karst:

Sažetak
Construction of grout curtains in karst terrains is primarily connected with dams and reservoirs. Their role is to increase watertightness and prevent progressive erosion. In this presentation hourly continuous measurement of groundwater level in two deep piezometers near the Ðale reservoir is analysed. The Ðale reservoir in the Cetina River began operation in 1989. The total length of the grout curtain is 3.9 km. It spreads 120m bellow the Ðale dam. First analysed piezometer A is drilled in the interior part of the system, between the reservoir and the grout curtain, while the second one B is located in its external part. Distance between them is 200 m. In natural conditions, prior the grout curtain construction, groundwater level fluctuation in both of them was similar (practically the same). Construction of the grout curtain extremely changed groundwater behaviour in each of them. During the six month of continuous monitoring, differences between groundwater levels in them range between +19.86 m (groundwater in B is lower than in A) and -12.77 m (groundwater in A is lower than in B). During the 77% of analysed period the groundwater level in interior piezometer A is higher than the groundwater level in external piezometer B. In other 23% of analysed period the groundwater level in outside piezometer B is higher than in inside A. The construction of the grout curtain caused unnaturally high hydrostatic gradients, which can accelerate the dissolutional expansion of karst fractures. As a result, unbearable leakage of the reservoir Ðale can occur over its lifetime. Careful analyses of groundwater level behaviour discover some other very important characteristics of karst underground morphology.

Izvorni jezik
Engleski

Znanstvena područja
Građevinarstvo

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