Research On The Pre-Displacement Of Surrounding Rock During Tunneling

By summing up the field monitoring during tunnel construction of some highways in Henan Province of China, the monitoring data combine with finite element model are employed to analyze the pre-displacement of the surrounding rock during the tunneling. The formula for calculating the pre-displacement of the surrounding rock is obtained from the elastic mechanics and integral creep model. Numerical results indicate that the pre-displacement appear at 1 similar to 1.5D away from the tunnel face in the beginning, and turn to a stable state at 2 similar to 3D away from the tunnel face; the pre-displacement of the surrounding rock accounting for 30% of the total displacement. Thereby, sufficient attention must be paid to the pre-displacement of the surrounding rock in design and construction of the tunnel.