This spreadsheet calculates the Effective Resilient Modulus of a subgrade from seasonal data taken throughout the year.
This allows the design to take account of the significant changes which can occur to the subgrades Resilient Modulus, for example when the subgrade is frozen in Winter or is saturated with melt water in Spring.
The spreadsheet calculates a relative damage value from the seasonal Resilient Modulus value, which is then averaged to give an overall effective Resilient Modulus which reflects the subgrade conditions throughout the year. This is calculated in accordance with AASHTO guidelines, and the effective Resilient Modulus can then be taken into an AASHTO flexible road design program such as AASHTO Structural Design.
Flexible Road Structural Design Spreadsheet - AASHTO Effective Resilient Modulus Spreadsheet.