Core Tip

As an important industrial base in China, Liaoning is known as the "Ministry of Equipment of the People's Republic of China". In many national major projects in various fields, 'Liaoning Manufacturing' has participated and contributed.

Recently, as the last section of the rock wall of a livelihood engineering project in Xinjiang collapsed, the "Endeavour" TBM designed and manufactured by NHI successfully penetrated, setting a world record for the longest single machine excavation of 26.521 kilometers, demonstrating the magnificent power of the "national treasure" and adding new footnotes to the "great treasure" of Liaoning.

March forward courageously

Showcasing the charm of 'Made in China'

The full section TBM is a key equipment that directly serves large-scale projects. Due to its ability to only advance and not retreat during excavation, it is also known as the 'brave warrior'. NHI is the earliest enterprises in China to conduct research and manufacturing in this field.

The geological conditions of the tunnel where the Xinjiang engineering project is located are complex, with relatively hard surrounding rock accounting for about 93.73%. For example, ultra hard rocks with a strength of over 200 megapascals and large areas of soft rock fractures require TBM to be designed with targeted measures for different strata and rock formations, "said Xu Chengfa, the technical director of NHI TBM Engineering Technology Company.

For underground excavation, the difficulty of construction varies greatly depending on the nature of the strata, and under complex geological conditions, the difficulty will be multiplied. Can domestic equipment withstand the test of long-term and long-distance continuous excavation?

Faced with doubts and concerns, NHI has lived up to expectations. Based on the technical reserve of the State Key Laboratory of full section TBM, combined with the calculation method hob layout and the verification method of the resultant moment hob distribution, the designers optimized the tool selection and trajectory distribution. For the first time in China, the 20-inch disc hob was selected. Multiple innovative technologies and design superposition ensured the excellent performance of the product in application.

During the excavation period, the equipment integrity rate of the "Endeavour" hard rock TBM reached 96%. While breaking the world record for the longest single machine excavation, it also set the record for the highest monthly footage of 752 meters and the highest daily footage of 40.3 meters.

Collaborative Innovation

Promote the industrialization of tunnel excavation technology

The large and non-retreating excavator is actually not far from daily life. Commonly known as the shield tunneling machine, is also a type of full section TBM widely used in urban rail transit, underground comprehensive pipe galleries, railway and highway tunnels and other projects. It has the characteristics of safety, speed, efficiency, not being affected by climate, being conducive to environmental protection and reducing labor intensity. It can achieve green construction and has a high degree of safety guarantee, becoming the mainstream technology and development direction of tunnel construction.

The development of NHI's technology and products has always resonated with the urban development of Liaoning and Shenyang. Adhering to the development model of cooperative innovation, NHI started in 2003 and entered the research and development field of full section TBM, achieving good and rapid development.

In 2006, the first 5.93-meter diameter hard rock double shield TBM manufactured by NHI was successfully produced. In June of the same year, NHI defeated multiple foreign competitors and won the manufacturing contract for six large slurry balanced shield tunneling machines, setting a historical record for international bidding of shield tunneling machines in China. In 2007, NHI acquired a French company, and in 2016, it acquired an American company, entering the forefront of the international market and leaping to become a world-class shield tunneling machine research and development base.

Chinese enterprises such as NHI have taken the path of batch quantitative design and manufacturing of domestically produced tunnel excavation equipment, promoting the industrialization of tunnel excavation technology in China.

Joint efforts to tackle challenges

Expand the path of localization development

The structure of TBM is complex, and it is a high-end equipment that integrates various technologies such as machinery, electrical control, and hydraulic. With tens of thousands of components working together, it can ensure foolproof operation during underground construction.

With the understanding of tunnel excavation technology and years of experience in manufacturing TBM, the localization rate of NHI's TBM continues to increase, but the main bearings have always relied on imports. In order to get rid of this "hard bone", the Institute of Metals of the Chinese Academy of Sciences, together with NHI, and with the strong support of the Shenyang Municipal Government, launched a breakthrough on the main bearing of the TBM, which has overcome more than ten key core technical problems, and finally opened up the "last mile" of the TBM that can be independently controlled.

During the experiment, technicians from NHI used a shield tunneling network control data platform for management, monitoring and recording the three practical application parameters of thrust, torque, and speed throughout the process. They also monitored the operating status of the main bearings of the excavation equipment under various combinations of excavation parameters in different strata. The current of the main bearing drive motor is normal, the temperature of the gear oil and main bearing is normal, the main drive system is running well, and all "mechanical, electrical, and hydraulic" systems meet the requirements for use... The localization verification work has been successfully completed.

After more than 20 years of exploration, NHI has now mastered the design, development, and manufacturing technology of a series of tunnel engineering equipment with independent intellectual property rights, including soil pressure balance shield machines, slurry balance shield machines, full section hard rock TBM, and coal mine TBM. More than 300 shield tunneling machines have been manufactured, significantly reducing product prices in the domestic market and saving a lot of construction funds for China.

Here, empowering innovative development in new fields through "technological fission" is becoming a powerful way to transform and cultivate new quality productivity. Innovative development, moving forward courageously, opening up infinite possibilities.

The TBM of "Endeavour"

The "Endeavour" hard rock TBM, designed and manufactured by NHI, with the full name of "7.83-meter open rock boring machine", is the world's first hard rock tunnel boring equipment with a design life of more than 33 kilometers, and its technical strength has reached the world's top level. As a core equipment, it has been fighting for 7 years in a livelihood engineering project in Xinjiang and has set a world record for the longest single machine excavation of 26.521 kilometers.