客运专线全风化砂砾岩路基填料特性

Subgrade-filled material properties of fully weathered gravelly sandstone for railway passenger dedicated line

将全风化砂砾岩作为客运专线路基填料,采用X射线衍射分析填料的矿物成分,测试了填料的自由膨胀率与阳离子交换率,比较了单个试件不同含水率循环击实和现场碾压下的粒径变化,分析了干湿循环作用下填料崩解和现场压实指标随时间的变化趋势,采用粗颗粒固结压缩试验测试填料变形特征。分析结果表明:填料不含亲水黏土矿物成分,自由膨胀率为23.6%,阳离子交换率为70.7mmol·kg-1,干湿循环下崩解率为0.81%,在动力作用下细颗粒含量为13.5%,雨后检测指标稳定,路基荷载下次固结系数为5.8×10-4。可见该填料具有很好的水稳性、动力稳定性与低压缩性,可用于客运专线路基填筑。

Fully weathered gravelly sandstone was taken as subgrade-filled material for railway passenger dedicated line, the mineral constituents of the material was analyzed by using X- diffraction, the expansion coefficient and cation exchange ratio were tested, the grain size distributions under loop compacting and field compacting were contrasted, disintegration cyclic tests under wetting and drying cycle were studied, and coarse granule compression test and relaxation behavior in site were analyzed. Analysis result indicates that the material does not contain hydrophilic mineral composition, its free-swelling index is 23.6%, its cation exchange rate is 70.7 mmol · kg^-1, its disintegration rate is 0.81%, its fine particle content is 13.5% under dynamical force, its detection indexes are stable after rain, its secondary consolidation coefficient is 5.8× 10^-4 under load. The experimental data show that the material has good water suitability, dynamical stability and low compressibility, and is a kind of better subgrade-filled material for railway passenger dedicated line. 5 tabs, 3 figs, 7 refs.