Swelling characteristics of andesite foundation induced by water immersion and their influence on ballastless track subgrade  

作　　者：DUAN Jun-yi YANG Guo-lin HU Min LEI Xiao-qin LIN Yu-liang 

机构地区：[1]School of Civil Engineering,Central South University,Changsha 410075,China [2]Key Laboratory of Mountain Hazards and Earth Surface Processes,Institute of Mountain Hazards and Environment,Chinese Academy of Sciences,Chengdu 610041,China

出　　处：《Journal of Mountain Science》2020年第4期1001-1012,共12页山地科学学报（英文）

基　　金：funding received from the National Natural Science Foundation of China(Grant Nos.51778641,51878667 and 51678571);the Fundamental Research Funds for the Central Universities of Central South University(2020zzts401)in support of this study.

摘　　要：To study the mechanical and deformation characteristics of ballastless track subgrade filled with micro-expansion fillers in a water-immersed environment, a physical model of ballastless track subgrade was constructed on a 1:2 scale with expansive andesite fillers. A water immersion test was carried out to model the soaking of the expansive soil foundation caused by rising groundwater. The swelling behaviors of the foundation and their influences upon the mechanics and deformations of the subgrade were analyzed. The lateral swelling pressure of the foundation and the heave of the subgrade obviously increased due to the water immersion, and the values were closely related to the overlying load and lateral restraint. The heave deformation of the double-line ballastless track subgrade showed significant nonuniformity along the lateral direction, causing the track slab to incline with a maximum inclination angle of 1.55×10^-3 deg. The heave of the foundation caused a heave in subgrade, but this transferred heave was significantly attenuated. The attenuation rate of the heave at the midline of the track slab was up to 13.38%. The attenuation characteristic can be fully utilized for the anti-heave deformation measures of railway subgrade in expansive soil areas.

关 键 词：High-speed railway Expansive ANDESITE HEAVE DEFORMATION Lateral SWELLING pressure INCLINATION angle DEFORMATION attenuation 

分 类 号：U213.1[交通运输工程—道路与铁道工程]