Currently

in China

compaction test with five-point method is the most basic earthwork test in the various specifications of soil test. The test has some drawbacks such as needing much more test soil and test time

great effort and meeting trouble in data processing. In order to overcome these shortcomings

different soil samples being prepared is dehydrated under the conditions of the timing constant pressure that its moisture content is higher than its plastic limit water content. There is a law that the moisture content after being dehydrated was stable

it is always lower than the optimum water content under standard compaction work. Based on the characteristic

optimum moisture content of the soil could be calculated by dehydrated moisture content and the correlation coefficient multiplied. Soil optimum moisture content and maximum dry density under standard compaction work could be obtained quickly and accurately using single-compaction method. After improving the method of compaction test

it is simple

fast and reliable comparing with the five-point method.