Research on the Stability and Support Effect of Earth Section of Hydraulic Tunnel Based on FLAC 3D

The stress of the surrounding rock of hydraulic tunnel can produce a stress load on the lining body, which may cause the crack failure of the lining. The distribution and deformation characteristics play a key role in ensuring the long-term stability of tunnels. Therefore, an analysis of the distribution characteristic is of great significance. This paper takes the branch tunnel in the Yellow River Diversion Project of central Shanxi as an entity for modeling, and uses the finite difference program FLAC3D for analysis and calculation. The research results show that before the support is strengthened, the compressive stress of feet-lock bolts has exceeded the compressive strength of the bolts, with obvious stress concentration at the arch feet; the deformation mainly occurs on the vault and the bottom plate; after strengthening the support, the deformation of the steel arch prop, the axial force of the steel arch prop, and the maximum tensile stress of the anchor rods are all reduced. The stable support effect can meet the requirements of construction and later operation.