Upper-bound analysis on the face stability of a non-circular tunnel

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• 作者：Qiujing Pan ; Daniel Dias ; ^{daniel.dias@univ-grenoble-alpes.fr}
• 关键词：Tunnel face ; Stability ; Limit analysis ; Non-circular section ; Safety factor
• 刊名：Tunnelling and Underground Space Technology
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：62
• 期：Complete
• 页码：96-102
• 全文大小：1469 K
• 卷排序：62

文摘

The present paper is devoted to the estimation of the safety factor of a tunnel face with a non-circular section using the upper-bound limit analysis in combination with the strength reduction technique. Thanks to the spatial discretization technique, an advanced 3D rotational collapse mechanism is extended to generate a failure mechanism for a non-circular tunnel face. The computed results are compared to 3D numerical calculations for a full face excavation as well as for a top heading excavation (a horseshoe shaped tunnel), showing a good agreement. A comparison with other approaches indicates that the presented approach gives conservative results and should be used for the safety factor assessment in the practical design. The effect of the cross-sectional tunnel shape on the safety factor is also discussed.