Paver Design

[ajk1]

I am checking the stress in pavers due to wheel load from a 6500 poound bobcat used to clear the snow.

Can anyone tell me what the approximate maximum axle load for this might be, or a specific web site where I can find this? I have tried looking at various manufactuers' data but they seem very meagre with this type of data.

If I assume that there must be a safety factor against overturning of 2.0, and that the maximum weight of snow when the bobcat lifts it onto the snow pile is 1500 pounds, and if I know the maximum extended arm reach of the machine and the wheelbase, then I could calculate the axle load, but I am not sure if the assumed safety factor of 2 against overturning is the appropriate number.

 

[ishvaaag]

This page seems to confirm a safety factor of 2 against overturning.

http://www.ehow.com/list_7629324_clark-632-skid-steer-specs.html

"Lifting Capacity

The maximum tipping load of the Bobcat 632 is rated at 2,100 lbs., with a rated operating capacity of 1,000 lbs. The maximum tipping load is the load on the bucket which will cause the Bobcat to tip over. The rated operating capacity, about half the tipping weight, is the recommended safe operating load."

 

[concretemasonry]

ajk1 -

What type of pavers are you referring to?

If they are the common interlocking concrete pavers, the stress is the pavers is not a factor because of the size of the pavers (no dimension over 10") and the high compressive strength (8000 psi minimum and possibly up to 12,000 psi).

These pavers are used for heavily loaded industrial and civil applications, such as airport taxiways (up to 747 planes) and ship unloading facilities (4 wheel straddle loaders carrying ship containers).

For these type of pavers the critical factor is the base beneath the paver surface. Typically, the pavers are 80 mm thick for streets and 100 mm thick for heavy duty. The increased thickness is used to provide a better interlock between the pavers.

The Interlocking Concrete Paving Institute (ICPI) has a very comprehensive web site that has many technical documents regarding the design, details and installation standards. This information is geared for the North American use, but is actually very similar to the other international standards.

Dick

Engineer and international traveler interested in construction techniques, problems and proper design.

 

[ajk1]

Concretemasonry - thanks for the info, but these are 5 foot square granite pavers. So I am still looking for an answer to my question, if anyone knows it.

 

[concretemasonry]

ajk1 -

I understand the materials you are concerned about and can assume the application. After that, the support mechanism for the "pavers/slabs" will depend on the support.

Dick

Engineer and international traveler interested in construction techniques, problems and proper design.

 

[Ron]

ajk1...according to Bobcat info, when at maximum bucket load, the load distribution is 70% front axle, 30% rear axle. That would make your example have an axle load of 5600 lb or 2800 lb/tire. That's a high wheel contact load, even though the axle load is not all that high. Because of the narrow tire spacing, I would expect overlap in the stress pattern.

 

[MiketheEngineer]

What is soil capacity - this may govern or "hurt" you and the pavers??