高速铁路基床表层级配碎石填料土体结构类型试验分析

Experimental Analysis on Soil Structure Type of Graded Gravelly Soil Filling Surface Layer of Subgrade of High-speed Railway

采用基于分界粒径-体积填充原理的粗颗粒土填料土体结构类型测定方法 ,分析高速铁路基床表层级配碎石填料的土体结构类型随颗粒级配的变化特点。试验表明:级配碎石填料中粗颗粒含量逐渐增多或细颗粒含量逐渐减少,引起土体结构由悬浮密实型向骨架密实型、再向骨架孔隙型转变。据此,提出级配碎石填料的土体结构分别为悬浮密实、骨架密实、骨架孔隙3种类型所对应的粒径级配控制值。研究成果对完善高速铁路基床多层结构体系中不同功能土层的碎石填料级配技术标准具有参考价值。

Boundary particle size-volume filling principle based gravelly soil structure testing method was used to investigate the variation of soil structure types with the change of particle size distribution in the grading areas. Test results showed that the gradual increase of coarse particles or gradual decrease of fine particles in the graded gravel filling would cause the soil structure to transform from suspension dense structure to skeleton dense structure, and finally into skeleton pore structure. Accordingly, the control values of particle size distri- bution corresponding to the three types of suspension dense structure, skeleton dense structure and skeleton pore structure were proposed for the soil structure of graded gravel filling. The research results provide a reference value for the improvement of grading technical standards for gravelly soil with different functions in the multilayer structure of high-speed railway subgrade.