This comprehensive review aims to summarize the current research progresses on fine sand performance as a subgrade filler. It encompasses the definition and classification of fine sand. a detailed discussion on its physical and mechanical properties, and an exploration of its dynamic characteristics. The review further explores various treatment methodologies for fine sand subgrade, including cement and fiber treatments, as well as innovative materials. Ultimately, the application of fine sand in subgrade engineering is thoroughly investigated, with a specific focus on windblown sand subgrades, sand-filled subgrades, and sand blowing subgrades. By synthesizing this information, the review seeks to contribute to the ongoing discourse on sustainable and environmentally responsible road construction practices, highlighting the potential of fine sand as a viable alternative to traditional soil-based subgrade fillers. Through a deeper understanding of fine sand's properties and treatment methodologies, road engineers can develop more effective and efficient strategies for utilizing this locally sourced material, thereby minimizing the environmental impact of road construction projects while ensuring the stability and durability of road structures. 去掉重复的内容，用英文回答（论文语言）

This review comprehensively examines the role of fine sand in subgrade engineering, emphasizing its potential as a sustainable and environmentally friendly alternative to conventional subgrade materials.

Definition and Classification

• Fine Sand Definition: The review clarifies the definition of fine sand, which is essential for understanding its applicability in subgrade engineering.1

Physical and Mechanical Properties

• Detailed Discussion: It delves into the physical and mechanical properties of fine sand, which are crucial for its performance as a subgrade filler.1

Dynamic Characteristics

• Exploration of Dynamics: The review explores the dynamic characteristics of fine sand, providing insights into its behavior under various conditions.1

Treatment Methodologies

• Cement and Fiber Treatments: Discusses traditional treatment methods, such as cement and fiber treatments, to enhance the properties of fine sand subgrades.
• Innovative Materials: Highlights the use of innovative materials in treating fine sand, aiming to improve subgrade performance and sustainability.

Application in Subgrade Engineering

• Windblown Sand Subgrades: Investigates the application of fine sand in windblown sand subgrades, focusing on its environmental benefits and stability.
• Sand-Filled Subgrades: Examines the use of fine sand in sand-filled subgrades, emphasizing its role in enhancing road structure durability.
• Sand Blowing Subgrades: Explores the challenges and solutions associated with sand blowing subgrades, contributing to sustainable road construction.

Contribution to Sustainable Practices

• Sustainable Road Construction: The review contributes to the discourse on sustainable road construction by advocating the use of fine sand as an alternative subgrade material, reducing environmental impact.2

Conclusion

• Strategies for Utilization: By understanding fine sand's properties and treatment methods, engineers can develop effective strategies for its use, ensuring road stability and durability while minimizing environmental footprint.3