Project introduction: G7 Beijing-Xinjiang Expressway is an important part in the national expressway network. Upon completion, it effectively reduces the pressure on G6 Beijing-Tibet Expressway and achieves significantly in social benefits. Many tunnels in Inner Mongolia Section are on denuded hills with obvious changes in landforms. For geology, the area mainly consists of Quaternary gravel, completely weathered and strongly weathered gneiss, with developed joint cracks, soft rock and damaged rock body. Surrounding rock is poor in self-stability at levels IV and V. As the tunnel is in extremely cold area and mountains contain much water, the tunnel faces many tests upon completion. 

All middle and short tunnels in the group are equipped with FL FLOLIC FOAM Freezing-thawing Resistant System for Tunnels in Extremely Cold Areas while long and large tunnels adopt the freezing-thawing system at 500m to the entrance and exit. FLOLIC FOAM insulating thickness: 45 mm.