Numerical Analysis on the Stress for the Portal of Two Parallel Tunnels

A numerical analysis on the portal of two parallel tunnels is carried out, to learn about the effect on the staggered space of two tunnels to the liner stress of tunnel´s portal. Thirty numerical models have been founded for analysis base on the different of staggered space of the two parallel tunnels. The results show that: if the clear distance and the separated mileage make change, the extreme value of maximum Mises stress value of tunnel liner is alterability and the section which locate the tunnel portal with maximum Mises stress is invariable; when the clear distance and the separated mileage are changed in a range, the effect of the clear distance and the separated mileage on the extreme value of maximum Mises stress value of tunnel liner is coupling.