Bearing Capacity of Temporary Road (Gravel)

[Xaved078]

Hi All,

How do I calculate the bearing capacity of a 2 layered (2X150mm = 300mm) gravel road sitting on geo-fabric(Road Base Type 2.5 - Australia) that has to endure a load of 300Kpa from the rigging machine?

The reason behind this is the access road is already built out there and there is no capacity to get the underlying soil test done, so we need to make sure the gravel layer itself has the bearing capacity to handle the load exerted by the machine.

We are doing the plate load test on the gravel surface but still, do not have information about the ground underneath.


Thanks

 

[oldestguy]

Missing is the stress-strain info for the fabric.

 

[Xaved078]

Hi oldestguy,

The technical properties of the fabrics are:
AS140 Geofab------ Grab tensile Strength = 400N
Trapezoidal Tear strength= 150
Elongation = 40%

Also we got the underlying soil result which is very poor. The granular (type 2.5) material looks ok (attached).

Any suggestion on how we get an idea about the bearing capacity of the crane pad (300mm layer of type 2.5 gravel) would be highly appreciated.


Thanks

 

[oldestguy]

I'd do a design for roadway and fabric reinforcement. A quick Google search of this subject comes up with several publications for this procedure tied to fabric stresses. You would have to make some assumptions as to the difference between the crane treads and tires. I was unable to copy those links when I did a search but with two different search wordings but several showed up. Some with USA State highway manuals. At least two came up with very weak
subgrade sites.

 

[oldestguy]

Try this address.

https://www.google.com/url?sa=t&rct...&isAllowed=y&usg=AOvVaw3r5ZTig6n8Histbt9oI0jx

 

[cvg]

the equipment appears to be supported on outriggers and the boom angle and reach may put more load on the front outriggers than the back. I don't see enough information presented to give the dimensions of the outriggers, load split between front and back or the additional loading due to the piles. with the poor roadway conditions, you may need to use crane mats

 

[Ron]

Agree with cvg...mats are probably your better option. Takes away a lot of the unknowns.

 

[Okiryu]

Try to Look at Koerner’s book. It has a good section about geosynthetics used for road reinforcement.