1. Activities
  2. Activity : Wave overtopping experiment bare clay section 1-1
  3. Help

If you need any explaination about this form contact ammar.aljer@univ-lille.fr

Activity Name:

Wave overtopping experiment bare clay section 1-1

Activity Numbre:

100

Activity type

Strength test

Involved Workpackage

Flood defences
Emergency response
Knowledge infrastructure

Objective

these tests are aimed at measuring the erosion rate of the clay layer underneath a grass sod on the landside slope of a levee, in order to enable the determination of the residual strength of the levee after failure of the grass. The results can be used to test and validate erosion models – both current models and future models.

Activity Brief descriptor

Right before the start of a test on a section, the upper 20 cm (including the grass sod) will be removed over a distance of 3.5 m long and 4m wide. This section was located in between 15 and 18.5m downstream of the outflow opening of the overtopping simulator and subjected to regular waves to be used in the calibration of an erosion relation

Linked to theme(s):

Breaching
Animal- & vegetation-induced anomalies
Erosion processes
Temporary levee repairs
Levee survey & monitoring technique
Prolonged collaboration

Activity Time

Start Date:

Feb. 1, 2022, 2:14 p.m.

End Date:

Feb. 1, 2022, 2:14 p.m.

Active time length:

Days:

1

Hours:

4.0

Other:

150 waves were released

Location

Levee stretch:

XI

Coordinates/ Latitude (WGS):

139727.0

Coordinates/ Longitude (WGS):

226774.0

Coordinates/ Altitude (mTAW):

None

Descriptor:

15-18.5 m downstream of the outflow opening of the wave overtopping simulator located on the dike crest. The clay was removed on the landside slope. The bottom end of the test section is approximately 1m from the landside toe.

Other references:

Data

Data: 1

Data type:
Description:
Date availability: None
Find at: https://stowanl-my.sharepoint.com/:f:/g/personal/llhpp_stowa_nl/Ejr1ykRvpXpGn68Jqkp1CEwBEgnYxnRQ16FdIVvNvRxkrw
Media avaliable:
Find media:

Relationships with other activities

Detaled information about the activity

Pre-conditions

The grass was removed over a section of 3.5m x 4m wide, and a depth of 20 cm using a crane.

Activity Descriptor

At the lower section, the test starts with 10 waves of 500 l/m, applying 60 l/s/m, to make things a bit easier in the field. In steps of 500 l/m this will be increased to 3000 l/m, next the maximum of 3400 l/m, followed by 3000 l/m decreasing in steps of 500 l/m to the minimum of 500 l/m. In total: 13 steps of 10 waves each

Equipments

Equipment: 1

- Wave overtopping simulator including pumps, pipelines, cranes for moving, etc
Wave overtopping simulator was used to offer a proper comparison against the erosion resistance of grass and as it is currently the most viable way of simulator up to real loading conditions in situ

Monitoring & Sensors

10 GoPro's for photogrammetry for monitoring the difference in erosion depth between waves and for determining the front velocities of waves
To be able to derive an erosion relation

this activity does not have sensors

Limits

During Activity

Post-activity conditions

Immediate Results

Results /Conclusion

Infrastructure Knowledge

Erosion relation for wave overtopping on clay
This activity was used to calibrate this relation

Other key information