• International Journal of Highway Engineering
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• v.6 no.3 s.21
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• pp.17-26
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• 2004

The in-situ California Bearing Ratio (CBR) test has been widely used for evaluating the subgrade condition in asphalt concrete pavements. However, because the in-situ CBR test is expensive and takes plenty of time for operation, it is very difficult to figure out the in-situ characteristics of subgrade strength in detail. For faster and economical operation, the Dynamic Cone Penetrometer (DCP) has been often utilized for estimating the subgrade strength in the field. The relationship between the CBR value and DCP index obtained from the DCP testing has been studied using the laboratory and in-situ testing by other foreign researchers. The objective of this study is to determine the relationship between in-situ CBR value and DCP index of the subgrade materials used in Korea. The DCP index for evaluating the strength of subgrade materials produced in Korea is presented in this paper. Research results propose the regression equation to explain the relationship between the CBR and DCP tests. The in-situ CBR values of subgrade materials range from 20 to 45% indicating the good and sound subgrade condition.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.2
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• pp.927-935
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• 2011

In-situ California Bearing Ratio(CBR) test has been widely used for evaluating the subgrade condition in pavements. However, because the in-situ CBR test is expensive and takes time for operation, it is difficult to figure out the in-situ characteristics of subgrade strength in detail. For faster and economical operation, the Dynamic Cone Penetrometer(DCP) has been often utilized for estimating the subgrade strength in the field. The purpose of this paper is to determine the relationship between CBR value and DCP index of the embankment constructed with mixtures of soil and waste lime. Waste lime used in this study is producted as a by-product in the manufacturing process of making $Na_2CO_3$ from local chemical factory in Incheon. In this field measurement, the geotechnical tests such as field water content, field density, field CBR test, and dynamic cone penetration test were conducted.

• International Journal of Highway Engineering
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• v.8 no.4 s.30
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• pp.75-85
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• 2006

Plate Bearing Test(PBT) and California Bearing Ratio Test(CBR) usually have been used to evaluate the bearing capacity of sub-layer in pavement system. However, these tests have shortcomings for which man powers and time are spent greatly. Many researchers proposed a simple Dynamic Cone Penetrometer Test(DCP) to evaluate the bearing capacity of sub-layers in pavement system. This study performed several field bearing capacity tests(DCP, PBT, CBR, FWD) to evaluate field performance of DCP on sub-base and subgrade at four test sections simultaneously. The results showed that DCPI, $M_{FWD}$, and $PBT_K_{30}$ are highly correlated, but CBR and other test are not. This study proposed the following regression models between FWD, DCP, and PBT: $$M_{FWD}=993.10\Big(\frac{1}{DCPI}\Big)+33.95\;R^2=0.77$$ $$M_{FWD}=3.7533K_{30}+23.085\;R^2=0.69$$