高铁无砟轨道基床级配碎石渗透稳定性研究

为研究高水力梯度下级配碎石渗透稳定特性，通过改进的渗透仪开展了路基基床级配碎石渗透稳定特性试验研究。结果表明:级配碎石渗流速度随水力梯度增加分为线性增长、非线性增长，渗透破坏急剧增长，随细颗粒含量增加明显降低，随压实度增大逐渐减小；临界水力梯度随细颗粒含量增大呈非线性增长，粒径小于0.1 mm的细颗粒含量超过5.5 %时，临界水力梯度增加幅度提高，临界水力梯度随压实度提高逐渐增加，压实度超过0.95时增幅比较明显；破坏水力梯度越大，级配碎石细颗粒含量越高，细颗粒损失量越多。

Study on Seepage Stability of Graded Gravel of Subgrade Bed in High-speed Railway Ballastless Track

In order to study the permeability stability characteristics of graded gravel under high hydraulic gradient, an experimental study on the permeability stability characteristics of subgrade bed graded gravel was carried out with an improved permeameter. The results show that the seepage velocity can be decomposed into linear growth, nonlinear growth and rapid growth followed by seepage erosion failure as the hydraulic gradient increases. The seepage velocity decreases with the increase of fine particle content as well as the increase of compaction degree. The critical hydraulic gradient increases nonlinearly with the increase of fine particle content, and when the fine particle content with particle size less than 0.1mm exceeds 5.5 %, the critical hydraulic gradient increases more. The critical hydraulic gradient gradually increased with the increase of compaction degree, and this increase is more obvious when the compaction degree exceeds 0.95. The more the failure hydraulic gradient, the higher the fine particle content of the graded gravel is, and the more the fine grain losses.