列车动荷载长期作用下圆形隧道衬砌损伤分布特征及演化规律研究 |
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引用本文: | 徐利辉,马蒙,刘维宁. 列车动荷载长期作用下圆形隧道衬砌损伤分布特征及演化规律研究[J]. 工程力学, 2020, 37(9): 144-152. DOI: 10.6052/j.issn.1000-4750.2019.10.0623 |
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作者姓名: | 徐利辉 马蒙 刘维宁 |
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作者单位: | 北京交通大学土木建筑工程学院,北京 100044 |
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基金项目: | 中央高校基本科研业务费(2018JBM036);国家自然科学基金项目(51978043) |
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摘 要: | 为研究隧道衬砌车致损伤分布特征及演化规律,该文采用规范推荐的混凝土单轴拉压本构关系推导了复杂应力条件下增量损伤本构关系,并基于此本构模型实现了ANSYS标准计算流程的二次开发。通过与单轴拉压试验结果对比验证了计算的可靠性。建立了地铁圆形隧道-地层耦合动力有限元模型,基于改进的Miner累积损伤理论,研究了列车动荷载长期作用下衬砌结构的损伤分布、动力响应、损伤增量及累积损伤演化规律。结果表明:衬砌长期车致损伤关于隧道中心线对称,主要分布于仰拱结构,分布角约120°;列车荷载作用点下方衬砌结构中出现两个损伤集中区,其损伤幅值较其他区域大;随累积运行次数的增加,损伤集中区内车致动应力幅值减小约83%,动应变幅值增大约150%;损伤增量与累积损伤均随列车累积运行次数增加而增大,且呈非线性关系;采用改进的Miner累积损伤理论可提高预测隧道结构疲劳寿命的准确性。
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关 键 词: | 地铁隧道 增量损伤本构关系 累积损伤理论 损伤分布 损伤增量 损伤演化 |
收稿时间: | 2019-10-25 |
DISTRIBUTION AND EVOLUTION CHARACTERISTICS OF CIRCULAR TUNNEL LINING DAMAGE DUE TO LONG-TERM TRAIN LOADS |
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Affiliation: | School of Civil Engineering, Beijing Jiaotong University, Beijing 100044, China |
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Abstract: | To investigate the damage distribution and evolution of the tunnel lining by train loads, the incremental damage constitutive relation under complex stress state was derived based on the uniaxial tension and compression constitutive relation in the Code for design of concrete structures and embedded into the standard calculation program of ANSYS. Its reliability was verified through a comparison with the uniaxial tension and compression experiment results. The coupled circular tunnel-soil dynamic FE model was then established. Based on the improved Miner’s cumulative damage theory, the damage distribution, dynamic response and the evolution of damage increment and cumulative damage of tunnel lining due to long-term train loads were studied. It is found that the long-term train-induced damage is symmetrical about the tunnel centerline, and mainly distributes in the inverted arch with an angle of 120 degree. There are two damage concentration areas right beneath the train load applying points, where the damage amplitude is larger than any other areas. With the increase in train operation time, the amplitude of single train-induced dynamic stress in concentration area decreases by about 83% whereas that of dynamic strain increases by about 150%. The damage increment and cumulative damage both increase nonlinearly with the increase in train operation time. Accordingly, the improved Miner’s cumulative damage theory could improve the accuracy for fatigue life prediction of tunnel lining. |
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