Influential factors of compaction test of soil

Compaction test is an indispensable experiment in civil engineering. This paper does some comparable experiments on influential factors of compaction test from the standard of compaction, soil kind, lubricating oil, the height which exceeds the height of tubeshaped objct and reused soil. At the same time the paper does also analyse results of comparable experiments. By comparable experiments which are done on influential factors of compaction, it is obtained that the maximum dry density increases while the best moisture content decreases with increasing the real hitting work; that the soil kind adopts natural soil or air-dried soil not reused and not allowing to adopt the soil used in compaction test; that the height which exceeds the height of tube-shaped objeci is less than 4 mm; that there is a thin layer petrolatum which is wiped on inboard wall of the real hit tube and protect tube. These positive results play a guiding role on compaction principle and test.