China has excavated a new 7.4 km expressway tunnel in Beijing on August 21, which is expected to feature 6 lanes for two-way traffic.
China excavates an expressway tunnel in Beijing using the shield tunneling method on August 21. (Photo: CFP).
The new tunnel is part of the eastern section of the 6th ring road project in Beijing. The deepest point of the construction is 75 meters underground, making it the deepest tunnel in Beijing. It is also the longest expressway tunnel in China constructed using the shield tunneling method.
Shield tunneling is a trenchless technique where a shield machine is used to cut through the earth, creating a borehole while providing a protective shield during the excavation process. The tunnel boring machine used in this new project is the largest diameter machine developed in China. Specifically, the machine has a boring diameter of 16.07 meters, a length of approximately 145 meters, and a weight of 4,500 tons, designed and manufactured independently by Chinese enterprises.
The tunnel has a total length of 7.4 km, comprising a 6-lane two-way expressway in the middle layer, smoke evacuation holes in the upper layer, and evacuation and rescue routes in the lower layer, according to the Beijing Capital Highway Development Company, the unit executing the project. In June, the western section of the tunnel was completed, while the eastern section was just finished on August 21.
The new tunnel project will create additional above-ground space to promote industrial development and plan large parks, contributing to the development of Tongzhou District in Beijing, as well as improving transportation in the Beijing-Tianjin-Hebei region.
