Abstract:
The durability of subgrade layer depends on the and compactness of the materials. However,
the commonly used method for checking the density of subgrade layer is costly and time
consuming. This study helps to eradicate these problems by introducing an alternative method
to check the density at field. In this research the relationship between Dynamic cone
penetrometer (DCP) and soil dry density was developed. The collected soil samples from
LGED road development projects at 6 different locations were selected to develop the
relationship. Grain size analysis, Liquid limit and Plastic limit, Specific gravity, Standard
proctor test, sand cone test were performed on these samples. In laboratory the standard ASTM
method was followed for compaction, a 4-inch diameter cylindrical mold and 2.5 kg hammer
with drop height of 12 inch was used to prepare the test sample. The test samples were prepared
at different density by varying the compaction rate and DCP penetration were measured. A
number of DCP test were performed on compacted test samples to determine the penetration
rate. Then the relationship were developed between DCP penetration and dry density. A linear
relationship was developed between DCP penetration and dry density. The relationship
developed from this study can be used to checked the density at field using DCP more
efficiently comparing with sand cone method.
