颗粒级配及初始干密度对路基翻浆冒泥特性的影响  

Influence of particle size distribution and initial dry density on the characteristics of subgrade mud pumping

作　　者：丁瑜 贾羽 王晅[1,2] 张家生[1,2] 陈晓斌[1,2] 罗昊 张宇 DING Yu;JIA Yu;WANG Xuan;ZHANG Jia-sheng;CHEN Xiao-bin;LUO Hao;ZHANG Yu(School of Civil Engineering,Central South University,Changsha,Hunan 410083,China;National Engineering Research Centre of High-Speed Railway Construction Technology,Central South University,Changsha,Hunan 410083,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410083 [2]中南大学高速铁路建造技术国家工程研究中心,湖南长沙410083

出　　处：《岩土力学》2022年第9期2539-2549,共11页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.51978674)。

摘　　要：重载铁路路基翻浆冒泥病害广泛存在且危害性极大,严重影响了轨道的稳定性和列车运行的安全性。铁路路基土体性质,如颗粒级配、孔隙比等对列车荷载作用下路基翻浆冒泥特性有显著的影响。利用自主研发的试验模型对粉质黏土与不同含量高岭土重塑试样进行翻浆冒泥试验,研究了不同颗粒级配(高岭土含量)、不同初始干密度(孔隙比)对循环荷载作用下试样的轴向应变、超孔隙水压力以及细颗粒迁移特性的影响。研究结果表明:随着高岭土含量以及初始干密度的增加,动荷载作用下试样产生的轴向应变、超孔隙水压力均减小,细颗粒迁移的平均高度降低,路基翻浆冒泥的程度减轻。通过试验发现,动荷载作用下试样内部的超孔隙水压力梯度是驱动路基土体细颗粒迁移的主导因素,试样产生的夹层对路基翻浆冒泥病害的发展具有一定的促进作用。The subgrade mud pumping of heavy-haul railway is widespread and harmful,which seriously affects the stability of tracks and the safety of train operation.The properties of railway subgrade soil,such as the particle size distribution,the void ratio,have a significant impact on the characteristics of subgrade mud pumping under the train load.In this study,a series of remolded samples consisted of silty clay and different contents of kaolin was subjected to mud pumping tests with a self-developed test model,and the influences of different particle size distribution(kaolin content) and different initial dry densities(void ratios) on the characteristics of axial strain,excess pore water pressure and fine particles migration under dynamic load were analyzed.The results show that with the increase in kaolin content and initial dry density,the axial strain and the excess pore water pressure of the samples,the average migration height of fine particles,and the degree of subgrade mud pumping all decrease.We also find that the excess pore water pressure gradient is the leading factor driving the migration of fine particles in subgrade soil,and the interlayer has a promoting effect on the occurrence of subgrade mud pumping.

关 键 词：翻浆冒泥 颗粒级配 初始干密度 轴向应变 超孔隙水压力 细颗粒迁移 

分 类 号：TU431[建筑科学—岩土工程]