Enerpac JS125 - Page 50

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Document number: ED.03783.00.001.ENG rev 4 Page 50 of 153
1.
Surface of one footprint
= width * length
(Skid width + 2 * Timber height)
*
[ 2 * (Skid height + Timber height )]
2.
Support ratio, to correct for the gaps
between the timbers
Support_Ratio =
Timber width / (Timber width + Timber gap)
3.
Pressure on the ground [metric
tonnes / m
2
]
RatioSupportfootprone
wheelperFtotalsafe
_int*_
__
=

Example of maximum load:
F
total safe
per wheel = 739 kN
Timbers for example:
Width 0.30 m
Height 0.30 m
Gap 0.05 m
Measures of one footprint:
Width: Skid width + 2 * Timber height = 0.2 + 2 * 0.3 = 0.8 m
Length: 2 * (Skid height + Timber height) = 2 * (0.2 + 0.3) = 1.0 m
Surface: 0.8 * 1.0 = 1.0 m
2
Support ratio 0.30 / (0.30 + 0.05) = 0, 86
Ground Bearing Pressure 𝜎 =
739
1.0∗0.86
= 859 kN / m
2

NB
Complete the checklist in appendix A “Checklist for planning” with the
calculated bearing pressure.
Attention
Never exceed the maximum Ground Bearing Pressure of the ground.