重载铁路路基冻害的防治措施效果分析

Effect Analysis of Prevention Measures for Frost⁃damaged of Heavy Haul Railway Subgrade

以朔黄重载铁路路基冻害段为研究对象,采用室内试验与数值模拟相结合的方式,分析了应力释放孔和井点降水两种措施的设置参数对路基冻胀变形的影响规律,并以冻胀缓解率为指标对比了两种措施缓解路基冻胀的效果。结果表明:冻胀变形量和冻胀率随孔洞率的增大而减小,随孔深的增大先减小后增大,随填充材料弹性模量的增大而增大;减小抽水井的布置间距,可明显增大井点降水法缓解冻胀的效果;应力释放孔的冻胀缓解率整体高于井点降水法,但后者的冻胀缓解率在特殊情况下可达到100%。建议在施工有限制或路基稳定系数较小时选取应力释放孔改善路基冻胀,在地下水位较高时选取井点降水法改善路基冻胀。

Taking the frost-damaged section of the Shuozhou-Huanghua heavy haul railway subgrade as the research object,using a combination of indoor tests and numerical calculations,the influence of the setting parameters of the stress relief holes and well-point dewatering measures on the frost heaving deformation of the subgrade was analyzed.The frost heaving mitigation rate was used to compare the effects of two measures to alleviate the frost heaving of the subgrade.The results show that the frost heaving amount and the of frost heaving rate decrease with the increase of the hole ratio,first decrease and then increase with the increase of hole depth,and increase with the increase of elastic modulus of filling material.Reducing the arrangement spacing of pumping wells can significantly increase the effect of well-point precipitation method to alleviate frost heaving.The frost heaving alleviate rate of stress relief hole is generally higher than that of well-point precipitation method,but the frost heaving alleviate rate of the latter can reach 100%under exceptional circumstances.It is recommended to select stress relief holes to alleviate subgrade frost heaving when the construction is restricted or the subgrade stability coefficient is small,and to select well-point precipitation method to alleviate subgrade frost heaving when the groundwater level is relatively high.