The inversion of mechanical parameters of weak surrounding rock in high-stress tunnel after casting anchor

This study investigates the performance of yielding bolt in a weak rock mass tunnel with high in-situ stress conditions. The genetic algorithm and the Komamura-Huang rheological model are combined to perform an inversion analysis of the mechanical parameters of the weak surrounding rock mass before and after implementing the anchoring system. The results based on an actual tunnel project suggest that the mechanical properties all enhanced in the anchoring tunnel section The elastic modulus of the surrounding rock increased by 45.7%, the cohesive force increased by 18.1%, and the friction angle increased by 2.92%. Hence, the yielding cable anchor can effectively prevent the squeezing deformation of the surrounding rock mass and improve the structural integrity of the tunnel lining. The performance of the anchoring system and the inversion process of the mechanical parameters can guide the design and construction of similar tunnel projects in weak rock mass configurationsKEYWORDS: yielding bolt, tunnel engineering, weak rock mass, parameter inversion, rheological model