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Honbest is the depth of the channel below the revetment.
Mbestorting is the horizontal projection of the length of the revetment
De "invloedslijn" is defined as "de uiterste lijn op het maaiveld waarvoor geldt dat als aan dijkzijde van die lijn het maaiveld wordt verstoord de veiligheid van de waterkering zakt onder de (volgens de toetsing) vereiste veiligheid, gelet op alle directe faalmechanismen"
NOTE: in WBI-2017 in case of a revetment the margin is defined in a slightly different way. Instead of Honbest, Hgeul is used: M = Max [ Mbestorting ; 2 Hgeul) ]
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NOTE: In case the user-defined sand type is "very fine sand", the breach flow criteria cannot be checked. The program indicates breach flow is possible and a warning message will be given in the Overall Results window.
Table with th average and local slope
from depth | to depth z [m +GL(a)] | Average slope | |||
|---|---|---|---|---|---|
Medium fine sand D50 > 200 μm and D15 > 100 μm | Coarse sand/Gravel D50 > 500 μm and D15 > 250 μm | ||||
| Local slope | Average slope 0 - z | Local slope | Average slope 0 - z | ||
0 | -5 | 1:2 | 1:2 | 1:2 | 1:2 |
-5 | -10 | 1:3 | 1:2.5 | ||
-10 | -15 | 1:4 | 1:3 | 1:3 | 1:2.5 |
-15 | -20 | 1:5 | 1:3.5 | ||
| -20 | -25 | 1:6 | 1:4 | 1:4 | 1:3 |
| -25 | -30 | 1:8 | 1:4.67 | ||
| -30 | -35 | 1:10 | 1:5.43 | 1:6 | 1:3.75 |
| -35 | -40 | 1:10 | 1:6 | ||
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