# A Study on the Depositional Law of Road Cutting in the Tengger Desert Desert
###### Abstract  
In this study, the characteristics of wind-blown sand in the hinterland of the Tengger Desert and the regularity of sand deposition in road cutting are studied by combining a field test and numerical simulation. Firstly, the meteorological observation system is used to obtain the long-term monitoring of the Tengger Desert hinterland, and the perennial wind speed, wind direction, and strong wind period are obtained. Then, a three-dimensional ultrasonic anemometer and stepwise sand accumulation instrument are used to measure the transient wind-blown sand velocity and density at the top of the cutting slope, which provide the basis and verification for the numerical simulation. Finally, Fluent software (2020R2) is used to establish two numerical models with and without grading. Based on [PERSON]'s two-fluid theory and fluctuating-wind user-defined functions, the movement of wind-blown sand in the cutting section of the desert hinterland is simulated, and the regularity of sand accumulation in the cutting section is obtained. The main conclusions are as follows: (1) The strong wind period in the hinterland of the Tengger Desert in 2021 mainly occurs from April to August, and the mainstream wind direction is concentrated in the WSW and SW directions. (2) The sand in the hinterland of the Tengger Desert is mainly medium-fine, and the particle size range is mainly concentrated at 0.075-0.250 mm, accounting for 98.2% of the total sand; the curve of the wind-blown sand density with height is oblique and L-shaped. (3) The method of grading excavation is beneficial to reduce the sand accumulation rate on the road's surface.  
Tengger desert; road cutting; wind-blown sand characteristics; oula-oula; sediment deposition +
Footnote †: journal: Applied Sciences  
Some scholars combined field and wind tunnel experiments to study the movement of wind-blown sand flow [6; 7; 8; 9; 10]. [PERSON] et al. [11] used wind tunnel experiments and Fluent software to simulate the fine-scale turbulent flow structure near two-dimensional sand lines, with special emphasis on the shear stress distribution of the sand bed. [PERSON] et al. [12] focused on studying the characteristics of the mass flux, mass concentration, horizontal velocity, and the transport rate of different particle-size groups and their relationships with their mass proportions in air and conducted an experimental analysis of these relationships in a wind tunnel with a particle-tracking velocimeter. [PERSON] et al. [13] used a laser-phase Doppler particle analyzer to study the influence of a slope on the sand transition behavior in a wind tunnel.  
The numerical simulation of wind-blown sand was developed into two main simulation methods in the 21 st century: Euler-Euler and Euler-Lagrange [14; 15; 16; 17; 18; 19; 20; 21]. Based on the field tests and Euler two-phase flow simulation, [PERSON] et al. [22] studied the influence of wind walls on the movement of aeolian sand flow. The sand-carrying capacity of an aeolian sand flow presents a negative exponential distribution with height, and the sand particles are mainly fine sand. [PERSON] et al. [23] combined experimental and numerical simulation methods to analyze the sediment accumulation law of the track structure.  
In the field investigation of the Tengger Desert, road cuttings were more likely to be buried by sand dunes than embankments. In this study, the perennial wind direction, wind direction, and wind-blown sand movement law of subgrade cuttings in the hinterland of the Tengger Desert were monitored on site, and the data were statistically analyzed to further explore the wind-blown sand structure and sand deposition of cuttings in the hinterland of the Tengger Desert, in order to provide a theoretical reference for the cutting design, prevention, and control of wind-blown sand disasters and safe operations in the hinterland of the Tengger Desert.