Abstract
Dykes provide protection from the risk of flooding to approximately 60% of the
Netherlands, by area. Unfortunately, most of the country’s major cities lie within this zone, placing a
large proportion of the population at risk should these flood defences fail. In total the Netherlands have
over 3800 km of primary flood defences protecting the coast and inland river systems with another
14000km protecting individual polders. Recent flood events in Europe caused by extreme rainfall have
raised concerns about the ability of the Dutch river dykes to resist similar events. This paper describes a
quantitative assessment of the vulnerability to flooding of a primary river dyke outside Dordrecht. The
dyke has shown significant signs of distress over recent years developing large tension cracks during
periods of drought on its leeward side, which have progressively increased in size. It is regularly
inspected by the local water authority due to its concerning visible deterioration. In this study, soil
uncertainty is quantified from in-situ geotechnical tests and laboratory tests. Several failure mechanisms
are then considered probabilistically, namely global stability, rapid drawdown, internal erosion and
overtopping. Fragility curves are generated for each failure mechanism describing how the probability
of failure would change if a given flood level were to occur, event trees are used to link the individual
failure mechanisms and quantify the system probability of failure. This paper illustrates the use of
fragility curves for earthwork asset management and advantages and limitations of the methodology
utilised are discussed.
Netherlands, by area. Unfortunately, most of the country’s major cities lie within this zone, placing a
large proportion of the population at risk should these flood defences fail. In total the Netherlands have
over 3800 km of primary flood defences protecting the coast and inland river systems with another
14000km protecting individual polders. Recent flood events in Europe caused by extreme rainfall have
raised concerns about the ability of the Dutch river dykes to resist similar events. This paper describes a
quantitative assessment of the vulnerability to flooding of a primary river dyke outside Dordrecht. The
dyke has shown significant signs of distress over recent years developing large tension cracks during
periods of drought on its leeward side, which have progressively increased in size. It is regularly
inspected by the local water authority due to its concerning visible deterioration. In this study, soil
uncertainty is quantified from in-situ geotechnical tests and laboratory tests. Several failure mechanisms
are then considered probabilistically, namely global stability, rapid drawdown, internal erosion and
overtopping. Fragility curves are generated for each failure mechanism describing how the probability
of failure would change if a given flood level were to occur, event trees are used to link the individual
failure mechanisms and quantify the system probability of failure. This paper illustrates the use of
fragility curves for earthwork asset management and advantages and limitations of the methodology
utilised are discussed.
| Original language | English |
|---|---|
| Number of pages | 8 |
| Publication status | Published - Jul 2023 |
| Event | 14th International Conference on application of Statistics and Probability in Civil Engineering - Trinity College Dublin, Dublin, Ireland Duration: 9 Jul 2023 → 13 Jul 2023 Conference number: 14 https://icasp14.com/ |
Conference
| Conference | 14th International Conference on application of Statistics and Probability in Civil Engineering |
|---|---|
| Abbreviated title | ICASP |
| Country/Territory | Ireland |
| City | Dublin |
| Period | 9/07/23 → 13/07/23 |
| Internet address |
