Geotechnical evaluation of aeolian sand and gravel soil as subgrade backfill materials in desert lake regions

Given the constraints of transportation conditions and cost, using traditional gravel soil with favorable properties for backfilling is often impractical in remote desert highway construction. Consequently, aeolian sand, which is abundant in these regions, provides a promising alternative for roadbed backfill. This study investigates the feasibility of substituting gravel soil with aeolian sand in typical desert highway construction. Comprehensive laboratory experiments were conducted to evaluate the physical and mechanical properties of both materials. The results indicate that although aeolian sand exhibits high shear strength and permeability, it poses compaction challenges due to poor particle gradation. The engineering parameters applied in the finite element numerical simulation model were systematically verified through field tests and compared with experimental results. It is used to simulate the behavior of aeolian sand, focusing on predicting foundation settlement and embankment slope stability under different compaction conditions. The analysis identifies the key factors influencing roadbed settlement and slope stability under applied loads. Based on these findings, the study offers theoretical guidance for optimizing the application of aeolian sand in desert road construction, aiming to reduce costs and logistical difficulties while ensuring a stable and durable roadbed.