Enerpac JS125 - Calculate the Ground Bearing Pressure Without Foundation

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Document number: ED.03783.00.001.ENG rev 4 Page 43 of 153
4.2.1 Calculate the ground bearing pressure without foundation
For calculating the ground bearing pressure of one barrel resting point area of a unit without
applying a foundation, the following formulas apply:
Data
depending
on the
operation
force on one unit
F
unit
kN
number of applied barrels
Nr_barrels
percentage of side load
P
%
height of the base plate of the swivel
Swivel
height
mm
Fixed data
own mass
one barrel
Barrel
mass
kN
top barrel
Top_barrel
mass
the unit
Unit
mass
measures of the plate
L
jack-up
,
B
jack-up
m
safety factor
S
reaction_width (related to the width of a barrel)
Reaction_width
mm
1. The force on one plate caused by the load and the side load is:
F
load and side load
= F
unit
(
1
/
4
+
1
/
2
p * Swivel
height
/ Reaction_width)
2. The additional force on one plate caused by the own mass of the system:
F
own mass
= (Unit
mass
+ Top_barrel
mass
+ Nr_barrels * Barrel
mass
) / 4
3. Total total force on one plate is
F
total
= F
load and side load
+ F
own mass
4. Take the safety factor into account:
F
total safe
= F
total
* S
5. The ground bearing pressure is:
σ = F
total safe
/ (L
jack-up
* B
jack-up
)