| 列车振动下隧道外承压水砂土层液化特性研究 |
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| 引用本文： | 陆志明,霍永鹏,巫志农,黄朝根,廖建东,张益瑄.列车振动下隧道外承压水砂土层液化特性研究[J].路基工程,2022,0(4):156-160. |
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| 作者姓名： | 陆志明 霍永鹏 巫志农 黄朝根 廖建东 张益瑄 |
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| 作者单位： | 1.西南交通大学交通隧道工程教育部重点实验室，成都 610031 |
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| 基金项目： | 国家自然科学基金项目（51878573） |
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| 摘 要： | 依托湛江海湾某下穿隧道，运用有限差分软件进行动力-地下水耦合数值计算，研究承压水砂土层的列车振动液化特性，并对其影响因素进行研究。结果表明:初始阶段超孔隙水压力主要集中在拱底位置，之后逐渐向拱顶处累积，因此拱顶和拱底处土层均为可能发生液化的薄弱位置；各监测点处超孔压比变化趋势较为相似，在短时间内迅速增至峰值，之后逐渐趋于稳定，且短期内不会消散，但拱顶处的超孔压比始终大于拱腰处，说明拱顶处地层更易发生液化。总体来看:各监测点最大超孔压比远小于1.0，均未达到液化条件；承压水水头越高、列车行驶速度越快、隧道覆土厚度越小、地层超孔压比数值越大，承压水砂土层越容易发生液化。
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| 关 键 词： | 高速铁路 液化特性 数值计算 砂土地层 超孔隙水压比 |
| 收稿时间： | 2021-08-31 |
Study on Liquefaction Characteristics of Confined Water Sand Layer outside Tunnel under Train Vibration |
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| Abstract: | Based on an underpass tunnel in Zhanjiang Bay, through numerical calculation of dynamic groundwater coupling by using the finite difference software, the train vibration liquefaction characteristics of confined water sand layer and its influencing factors have been studied. The results show that the excess pore water pressure is mainly concentrated at the bottom of the arch in the initial stage, and then gradually accumulates to the top of the arch. Therefore, the soil layer at the top and bottom of the arch are the weak positions where liquefaction may occur. The variation trend of the excess pore pressure ratio at each monitoring point is similar, which increases rapidly to the peak in a short time, and then gradually becomes stable, and will not dissipate in a short time. However, the excess pore pressure ratio at the top of the tunnel arch is always larger than that at the arch waist, indicating that the formation at the vault is more prone to liquefaction. Overall, the maximum pore pressure ratio at each monitoring point is far less than 1.0, which does not meet the liquefaction condition. The higher the confined water head, the faster the train speed, the smaller the tunnel soil thickness and the larger the stratum excess pore pressure ratio, the more likely the confined water sand layer is going to be liquefied. |
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