Abstract
A theoretical model was first established in order to evaluate the physical possibility of a dynamic response occurring around an existing tunnel under conditions of unloading wave incidence. Based on the steady state solution of the wave expansion approach, transient solutions subjected to unloading waves with different unloading times were obtained. A three-dimensional numerical model was then constructed in order to simulate dynamic responses around an existing tunnel under unloading disturbance forces. In the simulation, dynamic unloading was carried out through a new excavation after stress redistribution had been finalized in the examined tunnel, and parametric studies were then conducted for various unloading times, stress levels and tunnel spacing configurations. The results show that dynamic effects are induced around an existing tunnel under high levels of initial stress and at high unloading rates. The results of the dynamic analysis show that the PPV of unloading-induced microseism can be as high as that of an explosion-induced wave, and damage can be inflicted on existing tunnel walls (especially on the incident side of a tunnel). This dynamic effect diminishes dramatically with an increase in tunnel spacing and unloading times.
Sign-in/Register to access full text options 
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 callMore From: International Journal of Rock Mechanics and Mining Sciences
Disclaimer: 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.
