How many hydraulic rams do I need to prevent wall collapsing ?

[davekardle]

Homework Statement

rectangle wall with 3m height, 20 length, 6.0m width.
Rectangle filled with water.

The Attempt at a Solution

I've calculated the force acting on the wall to be: 1766 KN

I have a hydraulic ram exerting 5 tonnes of pressure.

How many do I need ?

Homework Equations

F=P.A

 

[rude man]

Average pressure = ρgd, d = 3m, g = 9.81 m-s^(-2), ρ = 1e3 kg/m^3.

So you know the force on each wall is ρAgd/2 assuming the walls can sustain max pressure of twice average pressure without breaking apart.

1 tonne = 1000kg*g of force. (It is not a measure of pressure but of force.)

The rest is 1st year high school algebra.

 

[davekardle]

Average pressure = ρgd, d = 3m, g = 9.81 m-s^(-2), ρ = 1e3 kg/m^3.

So you know the force on each wall is ρAgd/2 assuming the walls can sustain max pressure of twice average pressure without breaking apart.

1 tonne = 1000kg*g of force. (It is not a measure of pressure but of force.)

The rest is 1st year high school algebra.

That's exactly what I did:

Here's how I done:

F on each wall= (1766KN)

1T/m^2 = 9800 pa
5T/m^2 = 49000 pa

Force exerted by the hydraulic ram on the wall = 49000 X ( Depth x width ) = 882 KN for each Hydraulic ram.

So, to resist an opposite force of 1766KN I will need 2 Hydraulic rams.


Is this right ? thanks

 

[rude man]

F on each wall= (1766KN)

The force on two of your walls is greater than that on the other two since your room is not square-shaped.

 

[rezeew]

(force = pressure x area)





In order to accurately determine the number of hydraulic rams needed to prevent the wall from collapsing, we need to consider a few factors. First, we need to calculate the total area of the wall that needs to be supported. This can be done by multiplying the length and width of the wall. In this case, the total area is 20m x 6.0m = 120m^2.

Next, we need to consider the maximum force that each hydraulic ram can exert. You have mentioned that your hydraulic ram can exert 5 tonnes of pressure, which is equivalent to 49.05 kN. Therefore, to support the entire wall, we would need at least 1766 kN/49.05 kN = 36 hydraulic rams.

However, it is important to note that this is a simplified calculation and does not take into account any safety factors or potential variations in the force exerted by each ram. It is always recommended to consult with a structural engineer to determine the exact number and placement of hydraulic rams needed to support a wall. Additionally, the design and material of the wall and the strength of the ground it is built on should also be considered in determining the number of hydraulic rams needed for adequate support.