# Soil Spectral Behavior Related to Its Load-Bearing Capacity Based on Moisture Content
###### Abstract  
Soil's load-bearing capacity is a crucial property from which the ability of soil to resist the vertical deformation resulting from a normal load can be determined, and this property is essential for analyzing a vehicle's performance over soil terrain in terramechanics studies. Soil's moisture content has a significant impact on its load-bearing capacity and spectral behavior. This study aims to show the relation between the load-bearing capacity and the spectral behavior of sandy loam soil. The study presents the load-bearing capacity and color results of sandy loam soil at different moisture contents. The load-bearing capacity was measured using the Bevameter technique, and the color was measured using spectrophotometer technology that sends waves in the visible range (400-700 nm). The pressure-sinkage results of the tested soil show that with an increase in the moisture content, the bearing capacity of the soil decreases, and the color results show a decrease in the color reflectance with the increase in the moisture content. The measurements were performed in the laboratory of the vehicle technology department at Hungarian University of Agriculture and Life Sciences (MATE). soil load-bearing capacity; moisture content; Bevameter technique; soil color; soil spectral behavior; sandy loam soil Article  
[PERSON]; [PERSON] [PERSON]; [PERSON] Soil Spectral Behavior Related to Its Load-Bearing Capacity Based on Moisture Content  
used and are still using the Bevameter technique for measuring the bearing capacity of the soil (pressure-sinkage relationship) since it emulates the normal mechanism applied from the wheel on the soil. The Bevameter technique was developed by [PERSON] as a solution for ending up with suitable terrain properties when it comes to the off-road case of study [8; 9]. The load-bearing capacity of soil is measured by the Bevameter, which is a terramechanics measuring technique. The Bevameter technique was developed by [PERSON] to measure the soil's strength and its sinkage parameters upon being subjected to a running wheel. The wheel or the running gear connected to the vehicle applies both the normal load (vertical) and the shear load (tangential stresses) on the terrain. The wheel contacts the terrain, thus transferring the power taken from the transmission to the wheels as tractive forces and ending with the vehicle's movement. For simulating the real wheel-terrain contact case by studying the normal and shear loads applied on the terrain, the Bevameter technique is the best among the others [9; 10]. The soil's physical composition, wetness (water content), density, and initial compression condition affect the soil deformation caused by the vehicle's passage. The soil becomes more compact as the moisture increases [11]. The change in the moisture content of the soil changes its mechanical properties, thus influencing its load-bearing capacity [6]. Soil spectral behavior refers to the way that soil absorbs and reflects different wavelengths of light, which can be used to determine its physical and chemical properties [12]. The moisture content of the soil is one factor that can affect its spectral behavior, as soil with higher moisture content typically exhibits different spectral characteristics to dry soil [13]. The change in the soil moisture content changes its color [14], which is an important soil parameter to rely on when linked to the mechanical properties of the soil. There are different methods used for measuring soil color, and among these methods are the Munsell soil color charts 1975, which is a qualitative color estimation method [15; 16], and spectrophotometry technology, which is a precise and quantitative approach to specify the color [17; 18; 19]. Scientists have agreed that the reflected spectrum describes the color that we see with our eyes, despite some differences between humans due to differences in human vision.