The deterministic method is always adopted for the seismic resistance of loess tunnels. Considering the randomness of ground motions, the seismic fragility assessment of a shallowly buried circular tunnel in the loess region was carried out under pseudo-static conditions with seismic loading in the transversal direction. The displacements calculated by one-dimensional analysis were applied to obtain the seismic responses of the tunnel. Then the maximum damage index was output by a compiled Python program. The optimality of intensity measures was briefly discussed through the testing criteria of correlation, efficiency, practicality, and proficiency. Fragility curves were generated based on the fragility function in terms of peak ground acceleration (PGA) and peak ground velocity (PGV) to evaluate the tunnel’s seismic performance. The results show that the vulnerable parts that shift with different PGAs in conjugate directions are particularly prone to suffering damage. And PGA and PGV are identified as the appropriate indices for predicting the probability of tunnels in various damage states. Void behind the arch dome can increase the fragility of tunnels, and the tunnels embedded in softer sites become more vulnerable to seismic damage.

黄土隧道抗震计算多采用确定性方法。考虑地震动的随机性，在横向地震荷载的拟静力条件下，对黄土区浅埋圆形隧道进行地震易损性评估。应用一维分析计算的位移来获得隧道的地震响应。然后通过编译的Python程序输出最大损伤指数。通过相关性、效率、实用性和熟练程度的检验标准，简要讨论了强度测量的最优性。根据峰值地面加速度（PGA）和峰值地面速度（PGV）的脆弱性函数生成脆弱性曲线，以评估隧道的抗震性能。结果表明，在共轭方向上随不同 PGA 移动的易损部件特别容易受到损坏。 PGA和PGV被确定为预测隧道各种损伤状态概率的合适指标。拱顶后面的空隙会增加隧道的脆弱性，并且嵌入较软场地的隧道更容易受到地震破坏。