摘要
为研究季节性冻土区高速铁路路基修筑后冻融变形的分布规律,考虑冰水相变的作用,采用热弹性力学理论推导出冻土路基应力和变形的二维数值方程,建立路基力学有限元模型,实现路基温度场和变形场的耦合连续计算。而后考虑路基填土的不同冻胀率,研究哈尔滨—大连(哈大)高速铁路路基冻融过程中的变形和应力分布规律。计算结果表明:随着冻胀率的增大和冻深的发展,季节性冻土地区的路基竖向位移、横向差异变形、横向位移及拉应力等随之增加。路基表面的竖向位移有可能超过高速铁路路基变形允许值,并且路肩和边坡处可能在冻融过程中出现拉破坏而导致裂缝。进一步的分析表明:路基中水分重分布引起的土体冻胀率、融沉压缩系数等的变化是影响季节性冻土地区哈大高速铁路路基变形稳定性的主要原因。
To analyze the roadbed deformation distribution of high-speed railway（HSR） in seasonally frozen regions,thermo-elastic mathematical equations describing the stress and deformation of frozen roadbed were deduced considering ice and water phase transition. A finite element model was built,achieving continuous coupled calculation of geotemperature and deformation. Different frozen-heave ratios were adopted for the filling material along Harbin—Dalian HSR roadbed in deformation and stress analysis. The calculated vertical displacements,transverse deformation differences,horizontal displacements and tensile stress were found to increase with the frozen-heave ratios and frost depths. The calculated surface vertical displacements of roadbed are possible to exceed the allowed values of HSR standard. The calculated tensile failure occurrs in the section of roadbed shoulder and slope,indicating the possible occurrence of cracks. It is also indicated that the variation of the frozen-heave and the thaw-compression ratios caused by the water redistribution inside the roadbed under the action of geotemperature field are the main influencing factors to the deformation and stability of HSR roadbed.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2014年第12期2546-2553,共8页
Chinese Journal of Rock Mechanics and Engineering
基金
国家重点基础研究发展计划(973)项目(2012CB723301)
国家科技支撑计划课题(2012BAG05B01)
铁道部科技研究开发计划(Z2012–062)
关键词
土力学
季节性冻土
高速铁路路基
冻融变形
横向差异变形
冻胀率
soil mechanics
seasonally frozen region
high-speed railway roadbed
deformation during freezing and thawing
transverse deformation difference
frozen-heave ratio
作者简介
张玉芝（1979一），女，2007年毕业于天津大学建筑工程学院结构工程专业，现为博士研究生，主要从事冻土区高速铁路路基监测及信息处理方面的研究工作。E-mail：10116307@bjtu．edu．cn
