How to calculate the volume of earthwork for a dike? / Earthwork calculation for a dike using the mean area method

Sometimes it is necessary to calculate the volume of earth excavated or moved for construction projects such as levees. To calculate the earthwork volume for a dike, you can use the average area method. Here's how:

Calculation example

 

Take the example of a dike 75 meters long and 4 meters wide at the top. The depth of the dike is 1.45 meters every 15 meters, then increases to 1.70 meters, 1.95 meters, 2.25 meters, 2.55 meters and finally 2.80 meters. The side slope on both sides is 1:2.

Objective

We need to calculate the total earthwork volume in the dike using the average area method.

 

Procedure

Consider a section of seawall having a length of 15 meters (L1) as shown in the drawing above.

1. Tout d'abord, vous devez calculer la surface sectionnelle A1 pour la profondeur initiale d1. La formule pour calculer A1 est : A1 = [bd1 + d1²S]
2. De même, la surface sectionnelle A2 doit être calculée pour la profondeur donnée d2 après un intervalle de 15 mètres.
3. Le volume de terrassement pour une digue pour les 15 premiers mètres est égal à : V15 = [Am x L1] où Am = [(A1 + A2) / 2]
4. De manière similaire, le volume de terrassement pour chaque section de digue de15 mètres doit être calculé.
5. Le volume total de terrassement pour la digue est égal à la somme des volumes de terrassement pour chaque section de digue.

Voici les étapes de calcul détaillées :

Étape 1 : Calcul de la surface sectionnelle A1 pour la profondeur initiale d1

La formule pour calculer A1 est : A1 = [bd1 + d1²S]

En utilisant les valeurs données, nous pouvons calculer A1 comme suit :

A1 = [(4m x 1,45m) + (1,45² x 2)]
A1 = [5,8m² + 4,205m²]
A1 = 10,005m²

Step 2: Calculation of the sectional area A2 for the depth d2 after an interval of 15 meters

Using the given values, we can calculate A2 as follows:

A2 = [(4m x 1,70m) + (1,70² x 2)]
A2 = [6,8m² + 5,78m²]
A2 = 12,58m²

Step 3: Calculation of the earthwork volume for the first 15 meters

The earthwork volume for the first 15 meters is equal to: V15 = [Am x L1]where Am = [(A1 + A2) / 2]

Using the values ​​calculated previously, we can calculate V15 as follows:

Am = [(A1 + A2) / 2]
Am = [(10,005m² + 12,58m²) / 2]
Am = 11,2925m²


V15 = [Am x L1]
V15 = [11,2925m² x 15m]
V15 = 169,39m³

Step 4: Calculation of earthwork volume for each 15 meter dike section

 

Using the same steps as before, we can calculate the earthworks volumes for each 15 meter dike section: