Abstract

Tunnels constructed in soft rock and high field stress show significant gradual convergence with even after the excavation. This paper proposes a new visco-elastic-plastic solution for deep circular tunnel under squeezing conditions . The model is composed of Mohr-Coulomb plasticity and Burger's model for visco-elastic material. The state of the stress around the tunnel boundary and the tunnel wall displacement due to elasto-plastic behavior is determined using a conventional closed-from solution. Additionally, Kelvin type Burger's creep material model is used to determine the viscous behavior of tunnel wall convergence with time. Burger's model and Mohr-Coulomb's parameters are determined from unconfined compressive strength tests, triaxial tests , and creep tests on the cylindrical specimen of the host rock. The results of the proposed solution are compared with tunnel convergence data from laboratory-scale model test. The comparison show that the proposed solution reflects the tunnel's time-dependent behavior and adequately predicts the tunnel wall displacement compared to the experimental data.

Full Text
Published version (Free)

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 call