The geo-structures embedded in the multiple variable strata could be significantly affected by the geological uncertainty. The quantitative evaluation of geological uncertainty and its influence on the structural safety of embedded tunnels are seldom studied in the past. This paper aims to analyse the effect of geological uncertainty on the structural performance of tunnel using the proposed stochastic geological modelling framework. The geological uncertainty is characterized using an improved coupled Markov chain model based on sparse limited boreholes. A mapping approach is presented to solve the mesh asymmetry problem between the simulated strata and the numerical tunnel model. The tunnel structural performance analysis is then conducted based on the combined model considering the geological uncertainty and tunnel structure. A geological uncertainty index (GUI) is proposed to quantitatively evaluate the level of uncertainty of each borehole and the whole site. The effect of the borehole layout scheme on uncertainty evaluation of factor of safety of tunnel structure is investigated by a large number of stratigraphic realizations. Boreholes collected from Norway with relatively more considerable variability and from Shanghai with relatively more minor variability are adopted as case studies to illustrate the proposed probabilistic analysis framework. The results show that the boreholes with larger GUI values and closer to tunnel locations have a greater weight to affect the embedded tunnel structural performance in uncertain geological strata.

嵌入在多变地层中的地质结构可能会受到地质不确定性的显着影响。地质不确定性的定量评价及其对埋设隧道结构安全的影响，以往鲜有研究。本文旨在利用所提出的随机地质建模框架分析地质不确定性对隧道结构性能的影响。使用基于稀疏有限钻孔的改进的耦合马尔可夫链模型来表征地质不确定性。提出了一种映射方法来解决模拟地层和数值隧道模型之间的网格不对称问题。然后基于考虑地质不确定性和隧道结构的组合模型进行隧道结构性能分析。提出了地质不确定性指数（GUI）来定量评估每个钻孔和整个站点的不确定性水平。通过大量地层实现，研究了钻孔布置方案对隧道结构安全系数不确定性评价的影响。从变化相对较大的挪威和从变化相对较小的上海收集的钻孔作为案例研究，以说明所提出的概率分析框架。结果表明，在不确定地质地层中，GUI值越大、距离隧道位置越近的钻孔对埋入隧道结构性能的影响权重越大。通过大量地层实现，研究了钻孔布置方案对隧道结构安全系数不确定性评价的影响。从变化相对较大的挪威和从变化相对较小的上海收集的钻孔作为案例研究，以说明所提出的概率分析框架。结果表明，在不确定地质地层中，GUI值越大、距离隧道位置越近的钻孔对埋入隧道结构性能的影响权重越大。通过大量地层实现，研究了钻孔布置方案对隧道结构安全系数不确定性评价的影响。从变化相对较大的挪威和从变化相对较小的上海收集的钻孔作为案例研究，以说明所提出的概率分析框架。结果表明，在不确定地质地层中，GUI值越大、距离隧道位置越近的钻孔对埋入隧道结构性能的影响权重越大。从变化相对较大的挪威和从变化相对较小的上海收集的钻孔作为案例研究，以说明所提出的概率分析框架。结果表明，在不确定地质地层中，GUI值越大、距离隧道位置越近的钻孔对埋入隧道结构性能的影响权重越大。从变化相对较大的挪威和从变化相对较小的上海收集的钻孔作为案例研究，以说明所提出的概率分析框架。结果表明，在不确定地质地层中，GUI值越大、距离隧道位置越近的钻孔对埋入隧道结构性能的影响权重越大。