Abstract

The frost heave caused by the stagnant water may seriously threaten tunnels’ operation safety and service life in seasonally frozen areas. This paper aims to put forward new insights for the accurate evaluation of the frost heaving stress and the prevention of frost damage in seasonally frozen-region tunnels. Firstly, based on the local frost theory and local deformation theory, a new calculation model of the frost heaving stress caused by stagnant water is established. In this model, the space of stagnant water is simplified as the three-axis semi-ellipsoid, which is more in line with the actual situation. Then, the rationality of the new calculation model was verified by comparing it with the results of numerical analysis and previous studies. Finally, the effects of the crucial parameters in the calculation model were also conducted by the univariate method. The results show that the theoretical model is in good agreement with the numerical simulation. The theoretical analysis exhibits the more conservative results, which may provide a practical approach for damage assessments and frost preventions in the case of a lack of observed in-site data. Besides, some significant suggestions about the construction and design of seasonally frozen-region tunnels are obtained.

摘要

在季节性冰冻地区，积水造成的冻胀可能严重威胁隧道的运营安全和使用寿命。本文旨在为准确评估季节性冻胀隧道冻胀应力和预防冻害提出新的见解。首先，基于局部霜冻理论和局部变形理论，建立了滞水引起的冻胀应力新的计算模型。该模型将滞水空间简化为三轴半椭球体，更符合实际情况。然后，通过与数值分析和前人研究结果的对比，验证了新计算模型的合理性。最后，计算模型中关键参数的影响也采用单变量法进行。结果表明，理论模型与数值模拟吻合较好。理论分析显示出较为保守的结果，在缺乏现场观测数据的情况下，可为损害评估和防冻提供实用的方法。此外，还对季节性冻区隧道的建设和设计提出了一些重要建议。