Initial effects of heavy vehicle trafficking on vegetated soils

Abstract

Numerous studies have investigated the effects of vehicle trafficking on terrain and how soils and soil conditions affect the mobility of military vehicles. However, the majority of these studies were conducted on non-vegetated soils. The purpose of our four-year study is to investigate the effects of heavy vehicle trafficking on vegetated soils and to assess the impacts of vegetation, specifically grass, on vehicle mobility. The research program includes a series of experiments assessing the effects of trafficking, mowing, and burning on vegetated soil strength. Three test sections were constructed and planted with perennial ryegrass: one section represented outdoor field conditions and two were controlled indoor sections (sand and silty loam). Mobility parameters of motion resistance and traction were collected in each test section prior to trafficking by a large military vehicle (HEMTT). Before and after trafficking, each test section was characterized including soil strength, moisture content, soil density, and terrain disturbance. The results show that vegetation affects soil strength and thus the terrain impacts of trafficking. Additionally, treatment of the vegetation affects soil strength, especially in silty loam soils. This paper summarizes the first year results regarding soil condition, soil strength, and vehicle impact severity. Future years will assess the recovery of the vegetation in the tested areas with the ultimate goal of making recommendations for the treatment of vegetated military training lands.