Tunnel faces excavated under particularly difficult ground conditions are commonly supported. In case of conventional tunnelling, this support is provided by either improving the mechanical properties of the soil or introducing linear inclusions. This latter technique, consisting in the introduction of fibreglass pipes in the face, is particularly popular since it is very simple to tailor to the different conditions encountered during the excavation the reinforcement spatial distribution. In the current engineering practice, this stabilisation technique is designed by employing simplified approaches not allowing the face displacement estimation. For this reason, in case of deep tunnels in cohesive soils under either undrained or ‘partially drained’ conditions, these approaches cannot be employed. In this paper, the authors present the practical application of a new displacement based design approach, based on the definition of the face characteristic curve, putting in relation the face displacement to the stress applied on the face.

通常支持在特别困难的地面条件下开挖的隧道面。在常规隧道的情况下，可以通过改善土壤的机械性能或引入线性夹杂物来提供这种支撑。后一种技术包括将玻璃纤维管引入面部，因此特别受欢迎，因为根据开挖过程中遇到的不同条件调整钢筋的空间分布非常简单。在当前的工程实践中，这种稳定技术是通过采用简化的方法进行设计的，该方法不允许进行面部位移估计。因此，如果在不排水或“部分排水”的条件下，在粘性土壤中的深层隧道中，则不能采用这些方法。在本文中，