Dropping Weight Method to Determine Soil Bearing Capacity
We can determine the bearing capacity of the soil by using the following two methods.
- Dropping Weight Method
- Method of Slowly Applying Load
In this article, we are discussing the dropping weight method.
Dropping Weight Method
Dropping weight method is used to determining the approximate value of the soil bearing capacity.
⇨At first, assume a weight W that is dropped from a certain height on the bottom surface of the foundation trench.
⇨Due to falling a weight, an impression made on the soil of the bottom surface of the foundation trench, which is noted.
Now, bearing capacity of the soil can be calculated by establishing the following equation:
- R = Ultimate resistance offered by the soil.
- h = The height from where weight is dropped and up to the bottom surface of the foundation trench.
- D = Depth of the impression made on soil of the foundation trench.
- A = Cross-sectional area.
We know that the potential energy of the falling weight is equal to the energy lost in penetration.
So we can write, Wh = Rd
Or, R =Wh/d
Now, safe bearing capacity of the soil per unit area equal to = R/Af = Wh/dAf
where f is the factor of safety.
As it is an approximate method, so it is used only for construction of the minor structure.