ABSTRACT
With rapid developments in traffic construction in China, tunnel engineering plays an important role in traffic construction, and the safety of tunnel construction is top priority. In this paper, numerical simulation and practical engineering are combined to study the optimization of the initial support of shallow buried tunnel in weak surrounding rock. The following conclusions are drawn: (1) when the NATM is used for the initial support of shallow buried soft rock tunnel, the earlier the support time is, the smaller is the deformation of tunnel surrounding rock; (2) different initial support time of tunnel will lead to different plastic zones of surrounding rock. It should be closed into a ring as soon as possible to improve the overall stability of surrounding rock; (3) the thickness of initial support structure shall be reasonably selected according to the actual situation.
