On-field Assessment of Sub-Grade Uniformity using DCP

What is it about?

One of the key parameter for the performance of a pavement is uniformity of its sub-grade. In-situ assessment for the uniformity of the sub-grade is commonly carried out by measuring the density of soil mass. Measurement of the density is done by cutting a core from the soil mass. According to ASTM D6951-09 (2009) the soil density may be estimated if the soil type and moisture content are known from the Dynamic Cone Penetrometer (DCP) Penetration rate. Dynamic Cone Penetrometer (DCP) test is a soil-penetration test which is used for the measurement of sub-grade strength. In this paper, empirical correlations have been developed for estimation of in-situ density of the sub-grade material from DCP penetration rate and moisture content. These relations have been developed, using multi-linear regression analysis, for different soils, namely Black Cotton Soil, Yellow Soil and Moorum (lateritic soil) and also developed a generalized correlation for density using a power function model.

Featured Image

Why is it important?

Dynamic Cone Penetrometer (DCP) is a widely used field test for rapid determination of sub-grade strength of soil in field condition. In this method a cone is being penetrated into the strata and rate of penetration is noted. DCP has been intended to alleviate many of the deficiencies of systems that are manually pushed into soil or proving materials. The instrument is relatively simple in design and operation, and operator variability is reduced, which ultimately reduces the chance of error.

Perspectives