Full-Depth Asphalt

MarkW,

Besides the GW being shallow, what are the other conditions, loading, subgrade, etc.

Scotty

Yes you should expect problems.

One alternative is to place a geofabric wrapped compacted rubble layer (minimum stone size of 4-6inches) of approximately 12 inches depth on the top edge of the ground water table and then a thicker pavement over it. This is usefull over relatively short lengths as it is permanent and prevents the GW from entering the pavement material. This has been used successfully to treat wet areas caused by underground springs.

Otherwise all you can hope to do is to permanently lower the GW table by ag drains to reduce the risk of water entering the pavement.

The above is all dependant on loading, other ground conditions, topography, etc.