Abstract: Based on the viscoelastic artificial boundary element theory, the traditional straight artificial boundary was changed, and a new idea of using 2D arc consistent viscoelastic boundary element to simulate the artificial boundary of semi-infinite domain was proposed. Through case study, the establishment idea and the specific process set in the finite element software were introduced in detail, and the reliability of the 2D arc consistent viscoelastic boundary element model was checked. Meanwhile, the effects of the input source frequency domain, the elastic constants of the medium and the thickness of the element on the calculation results were discussed in depth, and the application range of the 2D arc consistent viscoelastic boundary element was given. The results show that the proposed element has better accuracy and stability than the common viscoelastic boundary element, which is simpler to use.

Key words: tunnel engineering; numerical simulation; arc consistent viscoelastic boundary; source frequency; elastic wave velocity; the element thickness

摘要： 基于黏弹性人工边界单元理论，改变了传统的平直人工边界，提出一种采用二维弧形一致黏弹性边界单元模拟半无限域人工边界的全新思路。通过算例，详细介绍了其建立思路及其在有限元软件中设置的具体流程，并对二维弧形一致黏弹性边界单元模型的可靠性进行验算；同时，深入讨论了输入震源频域、介质的弹性常数和单元厚度对计算结果的影响，并给出了二维弧形一致黏弹性边界单元的适用范围。结果表明，该单元的精度和稳定性均优于普通黏弹性边界单元，而且其使用起来更为简便。

关键词: 隧道工程；数值模拟；弧形一致黏弹性边界；震源频率；弹性波速；单元厚度