Numerical Stability Analysis of Large Section Tunnels Using the Double-Side Heading Method: A Case Study of Xiamen Haicang Evacuate-Channel

Large section tunnels have huge excavation spans, complex procedures, mutual influence among various multiple disturbances of the surrounding rock, and discontinuous connection linings under different which bring great difficulties to their construction. The Caijianwei Mountain No. 2 tunnel Xiamen Haicang Evacuate-channel project in China belongs a super large tunnel. tunnel’s maximum span reaches 30.52 m, area 421.73 m2. Its sequence, timing second primary lining support, temporary support disassembly, secondary double-side heading method were analyzed using numerical methods. sequence double side-heading from right pilot left then middle can avoid horizontal displacement at arch waist control deformation lining. two side was conducive bearing performance concrete crown. better protect safety waist. removal, effects on stress rock structures. In construction process, should be determined according actual site section. research results provide reference for design tunnels.