A New Criterion for Stability Analysis of Tunnel Surrounding Rock-Support Structure Based on the Convergence-Confinement Method

Abstract:

In the decision making of tunnel excavation and support scheme, stability analysis of surrounding rock-support structure is an essential link. Especially in fractured weak zone under complex geological condition, accurately measuring the deformation of support structure has an important significance for fast and safe construction. Based on the application of convergence confinement principle in judging tunnel deformation, this paper presented a new idea of using the ultimate displacement of tunnel initial support to analyze the stability of tunnel surrounding rock-support structure. Then, with a full investigation on the deformation and failure characteristics of highway tunnel surrounding rock at fractured weak zone, the ultimate displacement was got by using methods of numerical calculation and site monitoring measurement. Finally, the stability analysis of support structure in Zhongxing Tunnel was done. It can be arrived that there is a certain gap between true value u and measured value um of surrounding rock deformation. If the measuring points are installed after three excavation cycle, u is approximately equal to 1.6 um. then, based on the analysis of numerical simulation results and monitoring data of Zhongxing Tunnel, the paper indicated that the top and spring of arch are risk regions, reserved deformation of fractured weak zone is not enough, it should be adjusted from 10cm to 20cm.

• Periodical: Advanced Materials Research (Volume 629)
• Pages: 427-432
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.629.427
• Online since: December 2012
• Authors: Yong Kang, Bo Long Chai, Xiao Chuan Wang, Deng Li
• Keywords: Fractured Weak Zone, Stability Analysis of Support Structure, Ultimate Displacement Monitoring

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