Analysis of stress evolution characteristics during TBM excavation in deep buried tunnels

• DOI: 10.1007/s10064-019-01466-6
• Publication Date: 2019-01-21T12:32:21Z
• Authors: Yue Jiang; Hui Zhou; Jingjing Lu; Yang Gao; Chuanqing Zhang; Jun Chen
• Keywords: 0211 other engineering and technologies; 02 engineering and technology

Full-face tunnel boring machines (TBMs) are widely used in tunnel engineering projects as an efficient, safe and economical tunneling method. However, TBM excavation causes stress near the tunnel boundary that is disturbed and redistributed under high in situ stress. The changing stress of the surrounding rock can lead to rock failure and cause machinery damage, owing to large rock mass deformations. Research on the impact of TBM excavation on the surrounding rock has mostly focused on the stress magnitude, while the influence of the variation of stress orientation has not been considered. In this study, the practical simulation of a double-shield TBM (DSTBM) construction process was conducted using a three-dimensional (3D) numerical simulation. The rock mass stress changed intensely with the rotations of the principal stress axes as the tunnel face passed through the rock monitoring section during the tunnel excavation. Additionally, the significant influence of stress variation is discussed in qualitative terms, and the analysis results of the stress path are presented. Moreover, using a new self-developed laboratory apparatus, the actual stress path of the surrounding rock is proposed under conditions of a changing principal stress magnitude and changing rotation of the principal axis during the process of TBM excavation.