http://www.sd.xinhuanet.com/sd/jn/2017-06/16/c_1121154989.htm
Qilu Evening News
reporter learned from the Traffic Commission of Ji'nan City, after a bitter battle, at 20:47 on June 14th, the longest tunnel of the Second Ring East Road South Extension Project - the right hole in the tiger mountain tunnel.
the left hole of the tiger mountain tunnel is 1740 meters long and the right hole is 1888 meters long. The maximum excavation single hole width is 20.08 meters, and the cross section is arranged in four lanes. It is the largest single tunnel across the road in the country. The construction difficulty of the tiger mountain tunnel is the first in the 6 tunnels of the entire 2nd Ring East (South) extension line project. It is the key control project for the whole project to be completed on schedule. The tunnel passes through multiple contact alteration zones, karst development zones and fault fracture zones, and the geological conditions are complex, which are the most difficult tunnels in the whole line construction. The construction problems such as large span, small net distance, long shallow burial, long Ming cave, poor surrounding rock, water seepage and other construction problems have been overcome successively.
