Abstract: This paper introduces the testing methods of cone penetration testing and conventional soil sampling. In the quality control of the site compaction, cone dynamic penetration test has the advantage of short testing period, low cost and continuous testing profile. A comparative study between the cone dynamic penetration testing and soil degree of compaction has been conducted at the same site. The nonlinear regression relationship can not only provide the uniformity of the back fill soil but also the degree of compaction of the backfill soils. It is concluded that the cone dynamic penetration test can be used to have an effective evaluation of the degree of compaction of backfill soils.

Key words: Backfill Soils, Uniformity, Degree of Compaction, Cone Dynamic Penetration Test, Geotechnical Drilling, Sampling, Quality Control