Mechanics Characteristic Analysis of Loess Metro Tunnel Structure in Soaking Surrounding Rock

Abstract:

In order to understand the influence on stress of surrounding rock and lining structure in metro tunnel after the loess is soaking, based on the Xi'an Metro Line 2, with the help of numerical simulation program, choosing tow working condition: before soaking and after soaking to carry out comparative trial, combined with the field monitoring data, we put forward that: After soaking the surrounding rock around tunnel top and bottom have some tendency to squeeze in , while the left and right side have tendency to run away, as far away from the tunnel ,the internal displacement of surrounding rock educes gradually; Inside the soaking zone, the maximum principal stress of surrounding rock after soaking is bigger than before, while outside the zone, it's contrary; After soaking the maximum bending moment and axial force of lining increases 7% and 15% respectively, and the rockbolts bear compressive force, they lost the supporting effect almost. In a word, if heavy rain floods into loess surrounding rock suddenly, in short time the metro tunnel is safe and stable, while for a long run, not timely waterproof and drainage will bring to the metro operation potential risk.

• Periodical: Advanced Materials Research (Volumes 594-597)
• Pages: 1163-1168
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.594-597.1163
• Online since: November 2012
• Authors: Jia Jia Zheng, Li Jian Wu, Run Gua Guo
• Keywords: Field Monitoring, Loess Metro, Mechanics Characteristic, Numerical Simulation, Soaking Surrounding Rock, Tunnel Engineering

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