摘要
为探究列车循环荷载作用下地铁隧道基底饱水风化软岩动力响应及长期沉降,选取南昌地铁基底不同风化程度泥质粉砂岩为研究对象,开展了室内动三轴试验,提出了考虑加载次数、动应力比、偏应力比等因素的全、中风化泥质粉砂岩的累积塑性应变数学模型,结合动力有限元软件进行动力响应分析。结果表明:在不同风化程度组合地层中,地铁隧道基底位于全风化软岩时,列车荷载产生的动应力、加速度竖向影响范围分别为16.0 m、7.0 m,位于中风化软岩时动应力、竖向影响范围分别为11.0 m、6.0 m;全风化软岩层的动应力和加速度峰值均大于中风化软岩层的;结合累积塑性应变数学模型,当地铁运营100 a,列车速度为110 km/h情况下,隧道基底位于全、中风化软岩累积沉降预测值分别为25.68 mm、17.98 mm;列车速度的改变对隧道底部风化软岩的长期沉降影响较小。
In order to investigate the dynamic response and long-term settlement of water-saturated weathered soft rocks at the base of subway tunnels under the cyclic loading of trains,this paper takes argillaceous siltstones with different degrees of weathering at the tunnel base of the Nanchang Metro as the research subject to carry out indoor dynamic triaxial tests.The paper proposes a mathematical model of cumulative plastic strain of fully-and moderate⁃ly weathered argillaceous siltstones considering the number of loading,the dynamic stress ratio and the deviatoric stress ratio etc.,and conducts a dynamic response analysis through dynamic finite element software.The results show that in combined strata with different degrees of weathering,the vertical influence ranges of dynamic stress and acceleration caused by the train loading are 16.0 m and 7.0 m respectively when the subway tunnel base is located in fully weathered soft rocks,and 11.0 m and 6.0 m respectively when located in moderately weathered soft rocks;also,the peak values of the dynamic stress and the acceleration in fully weathered soft rocks are both greater than those in moderately weathered soft rocks;furthermore,combined with the mathematical model of cumulative plastic strain,the predicted cumulative settlements of the tunnel base located in fully-and moderately weathered soft rocks are 25.68 mm and 17.98 mm,respectively,when the subway has been in operation for 100 years and the train is running at a speed of 110 km/h;and the variation in train running speed has less impact on the long-term settlement of the weathered soft rocks at the base of the tunnel.
作者
石钰锋
曹成威
谈亦帆
徐长节
章立辰
黄勇
SHI Yufeng;CAO Chengwei;TAN Yifan;XU Changjie;ZHANG Lichen;HUANG Yong(Jiangxi Key Laboratory of Geotechnical Infrastructure Safety and Control,East China Jiaotong University,Nanchang 330013;Jiangxi Research Center for Underground Space Technology Development and Engineering,Nanchang 330013;Jiangxi Province Architectural Design and Research Institute Group Co.,Ltd.,Nanchang 330006;Coastal and Urban Geotechnical Engineering Research Center,Zhejiang University,Hangzhou 310058;Shihutang Navigation and Hydropower Hub Branch of Jiangxi Port and Maritime Construction Investment Group Co.,Ltd.,Nanchang 330008)
出处
《现代隧道技术》
CSCD
北大核心
2022年第2期86-95,共10页
Modern Tunnelling Technology
基金
国家地区科学基金项目(51768020)
国家自然科学基金面上项目(42177162)
江西省交通运输厅重点工程科技项目(2019C0010,2019C0011,2020Z0001).
关键词
地铁隧道
风化泥质粉砂岩
室内试验
数值模拟
长期沉降
Subway tunnel
Weathered argillaceous siltstone
Indoor test
Numerical simulation
Long-term settle⁃ment
