Simulation of Excavation Operation on Double-Arch Tunnel

Double-arch was applied in an expressway tunnel where two cracked rocks were drilled through. Excavation method of 3-heading excavation is simulated by means of ANSYS to ensure the safety. Calculation method is the interaction of formation and tunnel. Effect of two construction sequence on the loading and deformation is analyzed and principal stress and displacement of key-points is calculated. It is found that the maximum deformation occurs on the vault and arch bottom, the sensitive position to the stress is present to the intersection point of middle wall and skewback of two holes, vault and hance. The result will be helpful for rational construction scheme, explain to the problem during construction and unreasonable measured results.