基于形态仿生理念的沙漠路基边坡结构设计与研究

A probe to the morphological bionic design of desert subgrade slope structure

为减少沙漠地区公路路基积沙,寻求一种输沙性能优异的路基边坡结构形式。受沙丘在自然状态下形成独特结构的启发,以新月形沙丘作为仿生研究对象,运用仿生学设计理念构建沙漠地区适宜路基边坡结构形式。基于沙丘形态统计特征,建立仿沙丘表面路基理论数学模型和有限元数值仿真模型,分析不同边坡形态下风、沙流相互影响特性,并对仿沙丘路基边坡结构形式进行优化,提出一种适用于沙漠地区的仿生路基边坡结构。研究表明:路基边坡结构形态不同会影响路基周围气流场,相对常规直线形路基边坡结构而言,仿沙丘形路基边坡结构在迎风坡、路面和背风坡速度恢复优势明显,可使沙粒获得更大动能,加速沙粒通过路基,降低沙粒在路基周围沉积。优化后的凹曲线形仿沙丘路基边坡结构积沙与路面沙粒体积分数均显著降低,可使风沙流快速通过路基,并便于施工,具有良好的输沙能力。研究成果可为沙漠地区公路安全运营和路基边坡结构设计提供参考。

In order to reduce the sand accumulation of highway subgrade in desert areas,a subgrade slope structure with excellent sand transport performance is necessary.Inspired by the unique structure of sand dunes in their natural state,the crescent-shaped sand dunes were used as the bionic research object,and the bionic design concept is used to construct the suitable roadbed slope structure in the desert area.Based on the statistical characteristics of dune morphology,a theoretical mathematical model and finite element numerical simulation model of imitation dune surface subgrade are established,the interaction characteristics of wind and sand flow under different slope morphologies are analyzed,and the structure form of imitation dune subgrade is optimized,and a bionic subgrade slope structure suitable for desert areas is proposed.Compared with the conventional linear roadbed slope structure,the imitation dune-shaped roadbed slope structure has obvious advantages in the recovery of windward slope,pavement and leeward slope speed,which can make the sand grains obtain greater kinetic energy,accelerate the passage of sand grains through the subgrade,and reduce the deposition of sand grains around the subgrade.The sand accumulation and pavement sand grain volume fraction on the optimized concave curved imitation sand dune subgrade slope structure are significantly reduced,which can make the aeolian sand flow quickly pass through the subgrade,facilitate construction,and have good sand transport capacity.The research results can provide a reference for road safety operation and subgrade slope structure design in desert areas.