Subgrade construction destroyed the natural state of the soil, resulting in loose structure, particle reorganization. To have sufficient strength and stability of the embankment and must be compacted to improve its compactness. Subgrade compaction job is to improve the strength and stability of technical measures.
(1) the subgrade should be tiered compact, uniform density.
(2) soil subgrade compaction degree of not less than table 3 provides
(3) when finer particles as filler, and moisture content of soil moisture content should be close to the best