Based on the structural behaviors of horizontal layered rockmasses,an optimization scheme of tunnel support was proposed.

By using numerical simulation method,the whole construction steps of Huomachong double-arch tunnel which located in the horizontal layered surrounding rock masses were analyzed.

In the existing buckling analysis of drill stem in horizontal condition,the drill stem is thought of as an even rod with equal diameter and sticked on the below wall of well on the action of deadweight,so it was simplified as simply supported beam compressed axially and supported evenly along its length by well wall.