Study on long-term settlement of silt foundation under train cyclic loading of subway tunnel

Journal Information

J. Hefei Univ. Tech. (Nat. Sci.), May.2023, Vol.46 No.5: 652-658, 708

DOI: 10.3969/j.issn.1003-5060.2023.05.013

Authors

ZHU Ying $ ^{1} $, QIAN Xiaohua $ ^{2} $, ZENG Changnü $ ^{3} $, ZHAO Jinxing $ ^{2} $, YI Lingbing $ ^{4} $

(1. Zhengzhou Metro Group Co., Ltd., Zhengzhou 450000, China; 2. Shanghai Tunnel Engineering Co., Ltd., Shanghai 200232, China; 3. School of Civil Engineering and Architecture, Henan University of Technology, Zhengzhou 450001, China; 4. Yellow River Engineering Consulting Co., Ltd., Zhengzhou 450003, China)

Abstract and Keywords

Abstract: In this paper, based on the project of Zhengzhou Metro Line 1 from the South Nongye Road Station to South Dongfeng Road Station, a drained dynamic triaxial test was conducted on silty soil, and the calculation formula of cumulative plastic deformation of silty soil was studied according to the test results. Then, a three-dimensional model was simulated to obtain the dynamic deviatoric stress induced by the cyclic loading of subway train. The long-term cumulative deformation of the tunnel foundation induced by the subway train with a radius of curvature from 250 m to 350 m and a train speed from 40 km/h to 200 km/h was predicted. It can be concluded that the silty soil is prone to vibration deformation, and most of the deformation occurs during the initial stage, which is different from that of soft clay. In this simulation, the cumulative deformation during 30 years is 20.33 mm for the curved tunnel with a radius of curvature of 350 m and a train speed of 80 km/h. The greater the speed of the train, the smaller the radius of curvature and the greater the dynamic deviatoric stress. The cumulative deformation is more sensitive to the train speed than the radius of curvature. There

Keywords: silty soil; dynamic triaxial test; subway cyclic loading; cumulative deformation

作者信息

朱颖 $ ^{1} $，钱晓华 $ ^{2} $，曾长女 $ ^{3} $，赵金兴 $ ^{2} $，易领兵 $ ^{4} $

（1. 郑州地铁集团有限公司，河南郑州 450000；2. 上海隧道工程有限公司，上海 200232；3. 河南工业大学土木建筑学院，河南郑州 450001；4. 黄河勘测规划设计研究院有限公司，河南郑州 450003）

摘要和关键词

摘要: 文章基于郑州地铁1号线农业南路—东风南路站实际工程, 开展粉砂土排水工况的动三轴试验, 基于动三轴试验结果提出粉砂土塑性累积变形计算公式, 并结合有限元模拟获得的地层动偏应力数据, 预测小曲率半径为250~350 m、列车速度为40~200 km/h时隧道地基的长期累积变形。研究结果表明: 相较于软黏土, 粉砂土更易受到振动变形破坏, 其初始阶段的变形量与变形速率更大; 根据数值模拟计算结果, 曲率半径为350 m、速度为80 km/h工况下运行30 a的累积沉降为20.23 mm; 列车行驶速度越大, 曲率半径越小, 动偏应力越大, 且相较于曲率半径的影响, 曲线隧道地基长期沉降对列车速度的敏感性更大; 曲线隧道设计、施工和运营时, 要综合考虑曲率半径和列车速度的影响, 当曲率半径为250~350 m时, 理论上, 列车速度宜控制在80 km/h以下, 而当曲线隧道曲率半径大于350 m时, 列车速度可适当调高。

关键词: 粉砂土；动三轴试验；地铁循环荷载；累积变形

Funding

河南省重点研发与推广专项科技攻关资助项目（212102110027）；河南省科技研发计划联合基金资助项目（222103810075）

合肥工业大学学报(自然科学版)

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