火山渣铁路路基的渗透稳定性研究

火山渣颗粒由于本身含有较多的蜂窝状孔隙,导致火山渣砾石土的渗透特性有别于普通的砾石土,使得由其填筑的铁路路基极易发生雨水下渗将填料中细颗粒带走的管涌式冲蚀破坏。据此,分析火山渣砾石土填料的渗透破坏类型,运用自制加工的垂直渗透仪测定雨水在路基中下渗时的水力坡降值与临界水力坡降值,探讨雨水渗透下火山渣砾石土路基的渗透稳定性。研究表明:火山渣砾石土填料的渗透破坏类型为过渡型,其发生渗透破坏的临界水力坡降值大于9.12,远大于雨水在路基中下渗时的水力坡降值1.02,表明采用火山渣砾石土填筑的路基在雨水的长期渗透冲蚀下不会发生渗透破坏。

Study on the Seepage Stability of Railway Embankment Filled with Volcanic Cinder Gravels

With respect to the high porosity in volcanic cinder gravel particles,the permeability of volcanic cinder gravels is different from common gravels,and the piping erosion damage may exist in the railway embankment filled with volcanic cinder gravels. Therefore,the types of seepage failure in volcanic cinder gravels are identified,the hydraulic gradient value and the critical hydraulic gradient value when rainwater infiltrates in the embankment are measured with self-made vertical tester,and the seepage stability of the embankment filled with volcanic cinder gravels is approached. The test results show that the seepage failure types of the volcanic cinder gravels are of transitivity; the critical hydraulic gradient value is more than 9. 12,which is much bigger than the hydraulic gradient value of 1. 02 when rainwater infiltrates; and the piping erosion damage shall not happen to the railway embankment filled with volcanic cinder gravels.