摘要
连续降雨条件下,风化红砂岩残积土路基瞬态饱和区动态水压力特征是深刻认识反复翻浆冒泥病害机制的关键。采用不排水动三轴试验,模拟路基瞬态饱和区列车加载频率和连续降雨条件下排水边界条件,开展路基瞬态饱和区动态水压力特征试验研究。分析了细颗粒含量对风化红砂岩残积土路基瞬态饱和区动态水压力的影响,揭示了路基瞬态饱和区细颗粒含量临界值约为25%。当细颗粒含量小于25%时,动态水压力随细颗粒含量的增加而增大;当细颗粒含量大于25%时,动态水压力随细颗粒含量的增加而减小。引入等效粒间孔隙比的概念,解释了细颗粒含量临界值的微观机制和物理意义。基于试验构建了考虑细颗粒含量的风化红砂岩残积土路基瞬态饱和区动态水压力经验模型,分析了模型参数随细颗粒含量变化的敏感性。该模型有助于工程技术人员预测连续降雨条件下铁路路基瞬态饱和区动态水压力。
The characteristics of dynamic water pressure in transient saturated zone of red sandstone residual soil subgrade is the key to deeply understand the mechanism of repeated mud pumping under the continuous rainfall condition. Based on the undrained dynamic triaxial test, the dynamic water pressure characteristics of the subgrade transient saturated area are studied by simulating the train loading frequency and the drainage boundary conditions under the condition of continuous rainfall. The influence of fine content on dynamic water pressure in transient saturated zone of red sandstone residual soil subgrade is emphatically analyzed, it is found that the critical value of fine content is about 25%. When the fine content is less than 25%, the dynamic water pressure increases with the increase of fine content. When the fine content is greater than 25%, the dynamic water pressure decreases with the increase of fine content. The concept of equivalent intergranular contact void ratio is introduced to clarify the physical significance of the critical value of fine content. An empirical model of dynamic water pressure in transient saturated zone of red sandstone residual soil subgrade is established based on the experiment and the sensitivity of model parameters is analyzed. The model is helpful for engineers and technicians to predict the dynamic water pressure in the transient saturated zone of railway subgrade under continuous rainfall.
作者
丁瑜
陈晓斌
张家生
贾羽
DING Yu;CHEN Xiao-bin;ZHANG Jia-sheng;JIA Yu(School of Civil Engineering,Central South University,Changsha,Hunan 410083,China;Key Laboratory of Engineering Structures of Heavy Haul Railway of Ministry of Education Central South University,Changsha,Hunan 410083,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2019年第12期4740-4750,4758,共12页
Rock and Soil Mechanics
基金
国家自然科学基金（No.51678575）
中国铁路总公司科技研究开发计划课题（No.2016G003-B）~~
关键词
风化红砂岩残积土
铁路路基
瞬态饱和区
动态水压力
细颗粒含量
red sandstone residual soil
railway subgrade
transient saturated zone
dynamic water pressure
fine content
