When tunnel cross obliquely with terrain contour

and terrain has bigger ups and downs

using half subgrade and half tunnel structure at portal section can effectively reduce the damage to the natural environment

and ensure that the tunnel have enough thick soil cover.The construction process of this structure is complex

and the force during construction is complicated.So the difficulty of construction is great.In order to ensure the safety of tunnel construction

dynamic information of surrounding rock and supporting structure must be grasped by monitoring.The monitoring plan and relevant results of half subgrade and half tunnel structure at portal section of Dianhuiping tunnel is introduced.Monitoring results show that the structure is safe and stable in the process of construction

and this structure is a good method to solve these problems.These sensors can effectively complete relevant monitoring task.