Discussion on the compaction degree index of subgrade filled with laterite

Laterite soil is one of the typical and special soil.There are clearly states in the technical specification of highway subgrades that the compaction degree can be reduced according to the specific condition when the subgrade constructs with special fillings.Moreover,the subgrade can't be filled directly with high liquid limit and high plastic index soils.By using the laterite of one highway,a series of compaction and California bearing ratio(CBR) tests are carried out;the results indicate that laterite is sensitive to water strongly;the water content corresponding to the maximum CBR is 3 % greater than the optimal one.In addition,according to the rules that strength,compressibility,swelling-shrinkage,permeability indexes change with compaction degree,the compaction degree of laterite which is as sub-embankment filling can be reduced by 2.5 %,the water content is around 35 % during compaction.