Abstract:
The subgrade bearing capacity is an important parameter in flexible pavement
design, and it is largely influenced by the variation of subgrade moisture. California
Bearing Ratio (CBR) is the most popular method of assessing the subgrade
bearing capacity. It compares the load required to make a particular penetration on
a given subgrade with the load to make the same penetration on standard material.
Although it would be beneficial to perform CBR tests at more frequent intervals
on a road section to design, it would not be practical in certain instances owing
to the laborious and time-consuming CBR test process. In that case, developing a
method to predict the subgrade CBR based on the variation of moisture would be an
advantage. Accordingly, this study aims to assess the influence of moisture content
and the compacted density on the subgrade CBR value. Hence, the possibility of
developing a model to predict subgrade CBR was investigated. A series of standard
CBR tests were performed for different combinations of moisture and compaction
densities, and standard CBR values were estimated. Thereafter, a statistical model
was developed to predict the CBR value for the selected clay material and validated
with laboratory test results.
