Blockage of driftwood and resulting head increase upstream of an ogee spillway with piers

Accumulations of floating debris in reservoirs can have negative impacts on the safe operation of a dam. Thus, adequate spillway design in view of driftwood is of paramount importance. Herein, investigation of driftwood blockage with a reservoir flow approach was conducted. A laboratory facility was used to evaluate blockage of artificial stems at an ogee crested spillway equipped with piers. With a systematic approach, the effect of blocked stems on the head at a reservoir was qualitatively investigated. Experiments with manually blocked stems were performed to study the effect a blockage can have on the reservoir head. Experiments releasing 200 stems were performed to study jam shapes and their probability to cause a head increase. It was found that similar blocked volumes of stems had different effects on the head increase in the reservoir and were dependent on whether stems were in contact or not with the spillway crest. It was also found that an increasing head tends to decrease the blocking probability but not linearly.


Published in:
Sustainable and Safe Dams Around the World, 730-739
Presented at:
ICOLD Symposium, Ottawa, Canada, June 9-14, 2019
Year:
2019
Publisher:
Canadian Dam Association
ISBN:
978-0-367-33422-2
Note:
CP1905
Laboratories:




 Record created 2019-06-17, last modified 2019-08-12

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