7/9/2023 0 Comments Kigb freeze stateTo describe frost penetration profile characteristics, frost depth was characterized as shallow, medium, or deep. Table 7 summarizes typical frost penetration characteristics observed for each SMP site. Frost penetration profile showing solid freeze with partial spring thaw and refreeze. Frost penetration profile showing shallow freeze cycles in the fall followed by solid deep freeze with spring thaw.įigure 23. Frost penetration profile showing multiple freeze-thaw cycles.įigure 22. Figure 21 through figure 23 show examples of each of these commonly observed frost penetration profiles.įigure 21. Some of the commonly observed frost penetration profile characteristics were multiple freeze thaw cycles, shallow fall freeze with thaw followed by solid deep freeze with a spring thaw, and solid freeze with spring thaw and refreeze. Hence, knowledge of the maximum frost depth without an understanding of seasonal changes in frost penetration profile would not be enough for accurate characterization of seasonal changes in pavement structural characteristics. The review indicated that even for similar frost depths, the observed profiles varied from site to site and year to year. The changes in frost profiles over the cold seasons (fall, winter, and spring) were examined for each available year. Using frost estimates computed based on in-situ data, frost penetration profiles were analyzed for each of the 41 LTPP sites for all available years of data. Frost Penetration Profile Characteristics *** Possibility of frost beyond the last interpreted depth. These cases are noted by starred comments in table 6. For Arizona site 1024 and Nevada site 0101, the first interpretation depth was lower than the expected frost penetration depth. A summary of frost determinations is provided in table 6.įrost penetration profiles generated for all Minnesota, Manitoba, and Saskatchewan sites and site 4018 in New York indicate that frost penetration goes beyond the last interpretation depth. These months were determined by reviewing frost data for all available years and selecting the earliest month at the beginning of the freeze period and the latest months at the end of the freeze period. The first and the last months with freeze conditions are based on the worst case scenario. Maximum frost depth is used in the design to account for the worst case scenario.Īverage maximum freeze depth corresponds to the average of maximum frost depths based on all years used in the analysis and represents average or typical frost penetration conditions. Maximum freeze depth corresponds to the maximum frost depth for the year with the deepest frost penetration detected during the analysis. This information could be used to assess the severity of frost penetration at different LTPP sites. Using the results of the frost penetration analysis, average and maximum frost depths were determined, along with the first and the last cold month with freeze conditions for each LTPP site with in-situ measurement data. Observations discovered during the project are described in this section. Locations of LTPP SMP sites analyzed in this study. Detailed frost penetration results were reported in two LTPP computed parameters tables discussed later in this chapter.įigure 20. There were between 2 and 11 years of data analyzed for the different LTPP sites. Data from 21,953 dates were analyzed, and frost penetration depths were estimated. The schematic location of LTPP sites used in the frost penetration analysis study is shown in figure 21. The analysis results, as well as the LTPP computed parameters developed under this project, were reviewed thoroughly.įrost penetration analysis was conducted for 41 LTPP sites from the SMP I and II experiments. In addition to the reinterpretation of the previously processed data, all SMP II sections with ER data that had not been previously analyzed were analyzed using E-FROST, and new frost depths and layer estimates were prepared for the LTPP database upload. Using the E-FROST research analysis tool, all previously processed sections with ER data were reprocessed using the enhanced analysis methodology presented in chapter 4, and new frost depths and layer estimates were determined. FROST PENETRATION ANALYSIS RESULTS DATA ANALYSIS SUMMARY Long-Term Pavement Performance Computed Parameter: Frost Penetration CHAPTER 7.
0 Comments
Leave a Reply. |