摘要: |
Vehicle operations on cross-country terrain for military, commercial or industrial, and recreational purposes can disturb the terrain, especially during spring thaw season. Terrain disturbance from off-road vehicle operations can be measured in terms of rut depth and vegetation damage. Ruts occur when vehicle load is greater than the terrain's bearing capacity, especially in soft soils. Rutting is the physical disturbance of the soil, including compaction and deformation. Estimates of rut depth for wheeled and tracked vehicles in soft, unfrozen soils can be calculated using an empirical equation based on the vehicle and soil properties. The vehicle parameters include vehicle load, tire or tracked footprint area, and wheel slip. The terrain soil properties are very important elements for estimating rut depth, including soil type and strength. Rut depth measurements were collected from military vehicles during Stryker (wheeled) vehicle impact tests at three locations at Donnelly Training Area, Alaska, and from M60A3 (tracked) and HEMTT (wheeled) vehicles at Fort McCoy, Wisconsin, during spring thaw seasons. These rut depth data are coupled with information about vehicle maneuvers (multiple passes and turning) and soil properties, such as soil type, moisture content, and soil strength. The scope of this report is to compare the actual rut depth measurements with the empirical equations to relate the physical disturbance of the soil and vegetation to a severity index, quantify the volumetric soil displacement, and assess disturbance on winter operations. |