In-situ testing study on convection and temperature characteristics of a new crushed-rock slope embankment design in a permafrost region

摘要

For-the-purpose-of-enhancing-air-convection-and-controlling-solar-radiation,-a-new-crushed-rock-slope-embankment-design-combined-with-a-sun-shade-measure-is-proposed.-A-newly-designed-embankment-was-constructed-in-the-Tuotuohe-section-of-the-Qinghai-Tibet-Railway-and-a-field-testing-experiment-was-carried-out-to-determine-its-convection-and-temperature-char-acteristics.-The-results-show-that-distinct-air-convection-occurred-in-the-crushed-rock-layer-of-the-new-embankment,-especially-in-cold-seasons,-which-was-enhanced-when-it-flowed-upwards-along-the-slope.-This-preliminarily-indicated-that-the-new-design-of-the-embankment-slope-was-good-for-reinforcing-air-convection-in-the-crushed-rock-layer.-The-frequent-fluctuations-of-the-convection-speed-and-the-environmental-wind-speed-were-in-good-agreement,-suggesting-that-the-convection-in-the-crushed-rock-primarily-came-from-the-ambient-wind.-It-was-also-preliminarily-determined-that-the-new-embankment-had-a-better-cooling-effect-and-sun-shade-effect-for-decreasing-the-temperature-of-the-embankment-slope-compared-with-a-traditional-crushed-rock-slope-embankment,-and-the-mean-temperature-difference-between-them-was-up-to-1.7-°C.-The-mean-annual-temperature-at-the-bottom-boundary-of-the-crushed-rock-layer-was-obviously-lower-than-that-at-the-top-boundary,-and-heat-flux-calculation-showed-that-the-shallow-soil-beneath-the-embankment-slope-was-weakly-releasing-heat,-all-of-which-indicated-that-the-new-embankment-slope-design-was-beneficial-to-the-thermal-stability-of-the-embankment.-This-study-is-helpful-in-providing-some-references-for-improved-engineering-design-and-maintenance-of-roadbeds-in-permafrost-regions.