Evaluating the effect of soil structure on the ground response during shield tunnelling in Shanghai soft clay. (September 2016)

• Record Type: Journal Article
• Authors: Bian, Xia; Hong, Zhen-Shun; Ding, Jian-Wen
• Is Part Of: Tunnelling and underground space technology. Volume 58(2016)
• Page Start: 120
• Page End: 132
• Publication Date: 2016-09
• Subjects: Soil structure -- Tunnel -- Ground response -- Numerical modelling -- Soft clay; Tunneling -- Periodicals; Underground construction -- Periodicals; Tunnels -- Periodicals; Underground areas -- Periodicals; 624.193
• DOI: 10.1016/j.tust.2016.05.003
• Languages: English
• ISSNs: 0886-7798

Abstract

Highlights: We proposed a model incorporating soil structure that is suitable for tunnel analyses in Shanghai soft clay. Effect of soil structure on tunnel induced ground response and long-term behaviour was evaluated. The mechanism of the effect of soil structure on ground response was discussed. Abstract: When evaluating tunnel-induced ground response in Shanghai soft clay, the soil structure and its degradation behaviour of natural Shanghai soft clay during shield tunnelling should be properly considered. In this paper, a constitutive model that considers the initial soil structure and its destructuration is formulated within the framework of critical-state soil mechanics. The model is successfully calibrated and used to simulate the undrained behaviour of natural Shanghai soft clay. Based on the proposed model, finite-element analyses are conducted to simulate the short- and long-term ground responses induced by tunnelling at Shanghai metro line 2. The comparisons between numerical results and field measurements reported in literature indicate that the soil structure and the tunnel-induced destructuration significantly affects the magnitude and shape of the short-term surface settlement trough and horizontal displacement in Shanghai soft clay. The pore pressure variations around the tunnel are also affected by soil structure, which will significantly influence the long-term ground consolidation settlement in Shanghai soft clay.