Abstract: To study the influence of the compaction test types on the compaction characteristics of EPS particles light weight soil, and to reveal the compaction mechanism of light weight soil, three kinds of light weight soil with different EPS particle contents were prepared for four different types of compaction tests, i.e., standard light-type, standard heavy-type, small light-type and small heavy-type. The volume compression ratios of the EPS particles were measured, respectively. The results show that the dry density of the light weight soil first increases and then decreases with increasing the water content for the three mixed ratios light weight soil under all the compaction tests. The curve shapes are similar to parabola, and the optimum water contents of the three mixed ratios light weight soil are approximately 31%, 35% and 39%. For light weight soil having the same ratio, the maximum dry density of the standard light-type compaction test can be taken as the standard. The absolute growth range of the maximum dry density for the other three kinds of compaction tests is from ?0.014 g/cm3 to 0.072 g/cm3, and the relative growth range is from ?2.647% to 13.611%. The maximum dry densities obtained by the four kinds of compaction tests are basically the same. Due to the influence of size effect of the compaction cylinder, the maximum dry density of the small-type compaction test is larger than that of the standard compaction test when the compaction energy is same, but the difference of them is small. For the same compaction test type, it is found that the increase in the compaction energy has no obvious effect on improving the maximum dry density of the light weight soil. Under the compaction action, the EPS particles exhibit obvious plastic compression, and the compression ratio decreases with increasing the water content and the EPS particle content. The volume compression ratio varies in the range of 0.955% to 31.174%. It is feasible to determine the optimum water content and the maximum dry density of the light weight soil by using the small-type compaction test instead of the standard compaction test, which can provide reference for engineering design and construction of light weight soil.

Key words: light weight soil, compaction test types, compaction characteristics, optimum water content, maximum dry density, EPS, volume compression ratio