Single shield TBM is used for medium stability soft rock or fault zone tunnel excavation. Tunnel drive and lining are executed simultaneously.
Single shield TBM excavation principle:
Tunnel No. 7 of Taohe River Water Diversion and Supply Project
A single shield TBM with boring diameter 5.75m was deployed in this project. Its driving progress was extremely slow in broken sections encountered therein due to water ingress and sand inflow. In the beginning of 2011, as per client’s request for refurbishment, CREG refurbished the machine with modified design in which a bi-directional cutting & mucking system is introduced (this technology is applied for the first time in the world). Resultantly, the rolling problem occurred during tunnelling was effectively resolved. The refurbished TBM accomplished monthly progress of over 1500m in three consecutive months; furthermore, it set up a new world record in November 2011 for advancing 1868m just within one month.
Chongqing Mass Rail Transit Project
The entire tunnel length of Chongqing MRT Project is 37km with a 15.26km long hard rock section where nine hard rock TBMs with boring diameter of 6.28m were deployed. The maximum advance achieved daily was 33m and monthly 598m. This project was listed as a Major Sci-Tech Project in Henan Province as of 2010.
Single shield TBM