Under ultra-hard rock geological conditions, the excavation efficiency of the hollow cutterhead can be increased by 30%. It was learned on May 23 that the excavation-blasting machine test equipment jointly developed by Tsinghua University and China Railway Science and Industry Group has completed excavation tests under three important working conditions and is about to enter the promotion and application stage. This equipment is like an "all-rounder" in tunnel excavation construction, capable of adapting to construction under various complex geological conditions and providing a new solution for the construction of long and large tunnels.

At present, when China's long and large tunnels are constructed using tunnel boring machines, once complex geology such as hard rock, ultra-hard rock, rockburst, fractured zones, and large deformation of soft rock is encountered, equipment failures and construction delays are likely to occur, becoming a long-standing difficulty in tunnel boring machine construction. It is introduced that general shield machines are divided into ordinary shield machines and TBM tunnel boring machines designed for hard rock and ultra-hard rock strata. The excavation-blasting machine is a new type of tunnel excavation construction equipment that can adapt to construction under various complex geological conditions such as hard rock, ultra-hard rock, rockburst, fractured zones, and large deformation of soft rock. It has multiple excavation modes and can be called an "all-capable performer."

Unlike traditional shield machines and tunnel boring machines, whose cutterheads are a "shield," the cutterhead center of the excavation-blasting machine in front of us is a circular "hollow." It is precisely by using the hollow structure in the middle that excavation construction can cope with various different geological conditions.

It is introduced that, in addition to adapting to excavation under various geological conditions and improving construction efficiency, the excavation-blasting machine can also, under good surrounding rock conditions, use local materials and reuse them to produce aggregates, reducing project investment and achieving green construction. This equipment is expected to break the current dilemma of long and large tunnel construction and provide a new solution for the construction of long and large tunnels in fields such as large-scale water conservancy and hydropower projects, mines, highways, and railways.