Photo: China Railway Science and Industry Group

In a groundbreaking development, the world's first boring and blasting machine, jointly developed by Tsinghua University and China Railway Science and Industry Group, has successfully completed tunneling tests under three different conditions. The equipment is now set to enter the promotion and application phase.

Preliminary results from the tunneling tests have shown that the efficiency of tunneling with a hollow disc cutter can be increased by 30 percent in extremely hard rock geological conditions after advanced pre-splitting treatment, Science and Technology Daily reported on Monday.

This innovative equipment is expected to be used in large-scale water conservancy and hydropower projects, mines, as well as in the construction of highways and railways.

The boring and blasting machine combines the effectiveness of tunnel boring machines and drilling and blasting methods, offering multiple tunneling modes and promising new breakthroughs in the field of tunnel construction, according to a report by Science and Technology Daily.

According to Chen Jiale, a researcher at China Railway Science and Industry Group's high-end equipment manufacturing base in Wuhan, Central China's Hubei Province, the equipment can handle tunneling in hard or extremely hard rock geological conditions by utilizing the hollow disc cutter structure for advanced pre-splitting blasting. In better geological conditions, the full-face disc cutter can be used for tunneling.

Currently, tunnel boring machines face challenges -- once they encounter complex geology such as rock burst, crushing zone, and large deformation of soft rock, it is easy to cause equipment failure and construction delay. 

The boring and blasting machine is designed to address these challenges. For instance, in the case of large fault zones, smaller equipment can be used for advanced treatment through the machine's circular disc cutter. In situations with sudden mud or water inflows, the machine's circular disc cutter can be used for drainage, followed by grouting treatment.

"The development of the boring and blasting machine is expected to break the current construction challenges in large tunnel projects, providing a new solution for tunnel construction," Chen was quoted by Science and Technology Daily as saying.  

Chen highlighted three key functions of the machine: providing a quick passage for advanced treatment when encountering unfavorable geological conditions, combining tunnel boring and blasting methods for efficient and flexible construction, and utilizing on-site materials for green construction and cost reduction.

Global Times