Abstract
A new tunnel stability analysis method is proposed which is the external force increment method (EFIM) to transform the traditional tunnel stability ratio (<I>N</I>). The EFIM can be defined as the field stability raito (<I>N</I><sub>f</sub>), which consists of two newly defined parameters, namely the natural stability ratio (<I>N</I><sub>n</sub>) and the critical stability ratio (<I>N</I><sub>c</sub>). The relationship between the field stability ratio (<I>N</I><sub>f</sub>) and the change of external force is given. The tunnel stability plane and tunnel stability analysis plot are constructed. Based on this, the relationship between the field stability ratio (<I>N</I><sub>f</sub>) and the critical stability ratio (<I>N</I><sub>c</sub>) when the initial tunnel is stable or unstable is determined. According to the field stability rate (<I>N</I><sub>f</sub>), the critical stable state can be achieved with the tunnel by increasing two ways: one is to increase the external load to act on the external force on the tunnel, and the other is to reduce the internal support force of the tunnel. The relations for reaching the critical stability ratio (<I>N</I><sub>c</sub>) of the two EFIM are given respectively. The upper bound solutions of single tunnel, twin tunnels with the same diameter and twin tunnels with different diameters are analyzed by this method. The results show that the EFIM is reasonable and feasible for stability analysis of tunnel.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
