摘要: |
Drainage in pavement base/subbase layers is critical in achieving the service life of pavements. In practice, most design engineers assume a minimum permeability value in the hydraulic design of permeable base layers based on marginally accurate empirical relationships or limited laboratory testing, but virtually with no field verification. This lack of field measurements provides little confidence in the assumed design values and does not address the fact that permeability is a highly variable parameter. Recent studies have documented that the coefficient of variation (COV) of in-situ permeability is as high as 50%to 400%, making it the most variable engineering parameter in the pavement system. To overcome this problem, a new rapid in-situ permeameter test device that takes less than 30 seconds per test has been designed, manufactured, and validated in this research study. Brief details of the device and its concept, and the research approach to develop and validate the device are described in this report. |