基于无砟轨道膨胀路基的膨胀土分类分级试验研究

摘要

膨胀土治理关乎高速铁路的安全运营,而膨胀土治理的首要任务则是膨胀土的分类分级.现行的铁路规范中对于膨胀土的分类,适合于普通有砟轨道;对于无砟轨道却有局限性.原因在于现行规范把对于无砟轨道具有潜在危害的弱膨胀土划分为无膨胀土.本文依托某无砟轨道高铁工程为背景,以该铁路出现上拱病害地段的膨胀性泥岩为试验对象,进行了泥岩的自由膨胀率、液限、阳离子交换量、黏土矿物含量的实验.在参考现行规范的基础上,提出了新的分类分级的标准.经过验证,新的膨胀土分类分级标准简单易行,准确度较高.%Government of expansive soil relates to the safety operation of high-speed railway,but the identification and classification of expansive soil is the primary task of the that.The current railway standard for classification of expansive soils is only suitable for ordinary ballasted track, but which has limitations for ballastless track.The reason is that the current railway standard seems the potential harm for ballastless track of expansive soil as non expansive soil.Based on a ballastless track of high-speed rail project, taking the expansive mudstone in the arch disease section of the railway as the test object, the free swelling ratio, liquid limit, cation exchange capacity, and clay mineral content of mudstone were also performed.On the basis of reference to the current railway standard, the new identification and classification criteria are proposed.After verification, the new expansive soil identification and classification standards are simple and easy to operate, and the accuracy is high.