australian roads have a test called a CBR, that is "californian...

australian roads have a test called a CBR, that is "californian bearing ratio" which is used to determine the load a material can support in prolonged wet weather, i.e clay is very strong when dry but when wet it will sink a camel,so clay is unsuitable for use in roads because if it rains the road is ruined.

gravel is fine because wet or dry it can support trucks but the aust standards for this test insist that the material (roadbase) must be soaked underwater for 4 days with a weight of 5 kilos on top then a rod is inserted and the resistance wet is measured. However the question is..."does 5 kilos weigh the same at varying depths such as 200mm under and 500mm under the surface?"..