The giant dragon traverses, forging bravely ahead. TBM is the English abbreviation for Tunnel Boring Machine, hailed as a "traversal sharp tool," possessing advantages of speed, quality, economy, safety, and environmental protection, and is widely used in water diversion projects, transportation engineering, and other fields.On November 15, 2024, the 22-kilometer water diversion tunnel of the Gansu Tianshui Quxi Urban and Rural Water Supply Project, constructed by Sinohydro Bureau 3 Co., Ltd., was fully completed. This was the first time Sinohydro Bureau 3 used a small-diameter domestically-produced super-strong escape-type double-shield TBM for construction, and also the first time two domestically-produced TBMs were applied in the same project.

More than a decade of traversal, more than a decade of striving. Sinohydro Bureau 3 first introduced the TBM in 2012, and this "traversal sharp tool" has advanced steadily and repeatedly achieved new successes across various engineering projects. Today, Sinohydro Bureau 3's TBM fleet has reached 14 units, with 7 TBMs operating simultaneously, and cumulative tunneling mileage approaching 200 kilometers. TBM construction has become a core brand of Sinohydro Bureau 3.

Transformation: From "First Unit" to "Breakthrough"

Rivers and mountains as the battlefield, the mighty forces bravely compete; encamped on the snowy plateau, the hydropower iron army stands not idle. Looking back to 2012, when Sinohydro Bureau 3 first entered the TBM construction field, the Manufacturing and Installation Company also embarked on a development path of transformation from traditional electromechanical installation business to other civil construction fields. The Manufacturing and Installation Company urgently drew over 40 elite personnel specializing in machinery, electrical, hydraulic and other disciplines from various projects, formed the company's first TBM construction team, and swiftly rushed to the construction frontline in the Northeast, thus beginning the traversal journey of Sinohydro Bureau 3's first TBM.

Planning the overall situation, deploying the whole chessboard. Sinohydro Bureau 3 established a "TBM Expert Leading Group" composed of TBM experts, the Engineering Science and Technology Department, externally hired experts and other personnel, providing comprehensive technical support for TBM construction. During construction, exploring and learning simultaneously, continuously summarizing construction experience, tunneling efficiency kept improving, repeatedly setting new tunneling records, laying a solid foundation for the company's TBM brand creation.

The construction experience from the first TBM project accumulated strong momentum for subsequent project implementation. In August 2015, Sinohydro Bureau 3 won the bid for Section 3 of the Lanzhou Water Source Construction Project, with the Manufacturing and Installation Company as the responsible entity undertaking the construction of the 14.5-kilometer water conveyance tunnel in that section. In December of the same year, the first domestically-produced double-shield TBM "New Water Source No. 1," jointly developed with Sinohydro Bureau 3's participation, successfully rolled off the production line, filling a domestic gap, possessing completely independent intellectual property rights, and marking a major breakthrough in the field of domestically-produced large high-end equipment manufacturing. The project created two firsts in China's TBM construction field at that time: the first pressurized water diversion tunnel using TBM excavation and precast segment lining; and the first application of C60 high-strength concrete parallelogram segments in a water diversion project.

Facing new challenges, the Manufacturing and Installation Company of Sinohydro Bureau 3 took the initiative to seek breakthroughs. The Manufacturing and Installation Company dispatched a 14-person study and supervision team to participate in the entire process of equipment manufacturing and engineering assembly, learn double-shield TBM construction technology, and participate in the entire process of on-site assembly and tunneling construction of the first domestically-produced double-shield TBM, accumulating rich construction experience. In March 2016, the first domestically-produced double-shield TBM began excavation at the Lanzhou Water Source Project.

The geological conditions along the water conveyance tunnel are complex, requiring traversal of multiple faults and fractured zones, with some tunnel sections also experiencing large deformation of soft rock, posing significant TBM jamming risks and making construction extremely challenging. During TBM construction, the machine encountered jamming twice due to fault fractured zones and surrounding rock convergence deformation. Construction technical personnel actively explored and boldly practiced, and under the guidance of the company's expert group, creatively adopted a combined treatment method of "chemical grouting + cement grouting." Working hard in harsh conditions and overcoming difficulties, after 89 days and nights of strenuous effort, the TBM successfully passed through a 26-meter-long fault fractured zone and resumed normal tunneling. The project department also adopted the construction method of "excavating a horizontal pilot tunnel + releasing surrounding rock stress," using small pneumatic picks to excavate outside the shield, promptly applying steel supports while excavating, overcoming the risks of随时 collapse and rockfall outside the shield, solving the problem of TBM jamming due to surrounding rock convergence deformation, and continuously setting new tunneling records. After two years, in March 2018, the Lanzhou Water Source Project achieved full completion of the water conveyance tunnel.

Leap: From "Introduction" to "Leadership"

Rome was not built in a day. The shaping of the TBM brand requires the drive of "a thousand blows and ten thousand strikes still strong, regardless of east, west, south, or north winds" and the tenacity of "biting firmly onto the green mountain and never letting go, carrying one blueprint through to the end," in order to achieve the leap from technological "introduction" to technological "leadership" and become a pioneer in the TBM industry.

With the continuous enhancement of Sinohydro Bureau 3's TBM brand effect, in 2019, Sinohydro Bureau 3 successfully won the bid for the Gansu Tianshui Quxi Urban and Rural Water Supply Project. After completing the Lanzhou Water Source tunnel construction task, the Manufacturing and Installation Company began construction of the 22-kilometer water conveyance tunnel of the Quxi Urban and Rural Water Supply Project. This project is the first among TBM construction projects undertaken by the Manufacturing and Installation Company to use two 4-meter-class double-shield TBMs excavating toward each other from the tunnel outlet and inlet. The project is divided into two work areas, inlet and outlet, separated by more than 20 kilometers. The tunnel alignment must traverse the West Qinling Mountains, known as a "geological museum," and the project department faces dual pressure from construction management and construction difficulty. During TBM tunneling, after nearly 80 fractured zone treatments, using a fractured zone treatment technique of "implementing small-scale chemical grouting above the cutterhead and ahead of the tunnel face," the TBM successfully passed through a 910-meter-long fault fractured zone area, accumulating rich experience in fractured zone treatment for small-diameter TBM construction.

The Tianshui Quxi TBM Project, as Sinohydro Bureau 3's first project operating two TBMs simultaneously, is also the training base for TBM professional skilled personnel in the Manufacturing and Installation Company's TBM sector. Through the incubation of the Tianshui project, a "youthful, professional, and knowledge-based" TBM professional construction team has been cultivated. The trained professional skilled personnel have been deployed to multiple TBM construction projects, and the Tianshui project has become the foundation for the company's TBM projects to branch out and flourish.

With the dual support of performance and technology, the Manufacturing and Installation Company has successively undertaken TBM construction projects including the Baisha County Western Region Water Supply Project in Hainan Province, the C2 Section of the Circum-Beibu Gulf Guangdong Water Resources Allocation Project, and the water diversion tunnel of the Zhuxi County North-South Water System Connectivity (Eping Water Diversion) Project. The implementation of these projects has played a positive role in promoting Sinohydro Bureau 3's TBM brand.

"Only after enduring the bitter cold can the plum blossom fragrance be smelled." In recent years, the Manufacturing and Installation Company has continuously innovated and forged ahead in TBM technical transformation and construction technology management, achieving fruitful results and remarkable accomplishments. During construction, TBM technical personnel of the Manufacturing and Installation Company focused on summarizing and refining construction experience, successively obtaining more than 20 national invention patents and national utility model patents; completing the compilation of multiple PowerChina Group construction methods, water conservancy and hydropower construction methods, provincial-level construction methods, and industry standards; publishing more than 40 academic papers of various types in provincial and ministerial-level journals; and more than 20 achievements winning the Science and Technology Innovation Achievement Award of Sinohydro Bureau 3's mass innovation and efficiency activities. A large number of scientific research topics such as "Research and Application of Key Technologies for Double-Shield TBM Construction" and "Research on Key Technologies in the Application of Domestically-Produced Double-Shield TBMs in Water Conveyance Tunnel Construction" have won various awards from industry associations, PowerChina, and the National Youth Vocational Skills Competition.

Growth: From "Single" to "Alliance"

Unleashing talent vitality to provide strong support for high-quality project performance. The Manufacturing and Installation Company has always emphasized talent cultivation in the TBM sector, organizing various TBM construction professional training and learning sessions covering hundreds of employees, effectively improving the professional levels of project technical personnel and frontline workers. Among frontline production backbone personnel, many have obtained senior technician qualifications. Professional technical personnel have also served as specially invited experts, delivering academic exchanges at the hydropower industry technology and management seminars and the 5th National Tunnel Boring Machine Engineering Technology Seminar.

To thoroughly implement the work policy of "accelerating the cultivation of a knowledge-based, technology-oriented, and innovation-driven workforce" and further strengthen TBM brand building, in November 2022, Sinohydro Bureau 3's "TBM Tunneling Technology Innovation Studio" was officially inaugurated at the Tianshui Quxi Urban and Rural Water Supply Project Department.

The establishment of the innovation studio has been integrated into the project's technical management work. Led by the innovation studio, many technical difficulties in construction have been solved, such as fractured zone treatment in TBM construction and escape from jamming due to surrounding rock convergence deformation. It actively leads members and project technical personnel in carrying out mass innovation and efficiency activities, achieving many results, winning an excellent reputation, and playing a good demonstrative role. The innovation studio has become Sinohydro Bureau 3's leader in solving TBM construction technical difficulties and a technology leader in the small-diameter TBM construction field within the industry.

Integrating effective resources, strengthening innovation forces, and achieving vigorous development, the "Sinohydro Bureau 3 TBM Innovation Studio Alliance" emerged as the times require. In May 2024, led by the Manufacturing and Installation Company's "TBM Tunneling Technology Innovation Studio," and integrating the resources of the "Sinohydro Bureau 3 Shield Tunneling Technology Innovation Studio" and the "Sinohydro Bureau 3 TBM Innovation Studio," the "Sinohydro Bureau 3 TBM Innovation Studio Alliance" was established. Through means such as innovation task traction, aggregation of advantageous resources, and institutional mechanism guarantees, it gathers strength, deeply explores and researches key core technologies in TBM informatization, intelligence, green, energy-saving, and environmental protection construction, helps promote the resolution of "bottleneck" technologies, fights the battle for key core technologies, and further promotes the improvement of Sinohydro Bureau 3's TBM and shield tunneling construction technology and construction management levels.

With mechanisms, platforms, and carriers, talent in the TBM field continues to emerge in an endless stream. Individual honors such as the "Shaanxi Provincial May 1 Labor Medal," "Sanqin Craftsman," "Shield Tunneling Craftsman," "Shaanxi Provincial Technical Expert," "Shaanxi Provincial Technical Pacesetter (TBM Tunneling Technical Personnel)," and "Shaanxi Provincial Construction Craftsman" have also come pouring in.

All projects in the TBM sector of the Manufacturing and Installation Company consistently adhere to political guidance, emphasizing responsibility, valuing commitment, advocating dedication, and fulfilling missions. Through various activities, they continuously inspire the spirit of Party members to rise to challenges and strive hard, letting the Party flag fly high on the frontline of TBM engineering projects. The working environment inside the tunnel is poor—humid and hot. In tasks such as daily equipment inspection, maintenance, and solving jamming problems, Party members are present everywhere. They have different specialties and different positions, but when facing "urgent, difficult, dangerous, and heavy" tasks, they always charge ahead and bravely shoulder heavy burdens, deeply rooted at the forefront of all TBM construction fields, interpreting the original aspiration and mission of Party members through practical actions. It is precisely because of the hard work and dedication of these Party members rooted in the frontline that one tunneling goal after another has been achieved and one project after another has been successfully performed.

Crossing mountains and seas, never stopping. With the gradual improvement of Sinohydro Bureau 3's "1+5+N" overseas business system and the continuous deepening of the "globalization, whole-situation, and localization" development of international business, the Manufacturing and Installation Company rides the east wind of vigorous international business development, sets sail, and boldly "goes global." On November 28, 2024, Sinohydro Bureau 3's first overseas TBM project—the first TBM "Dayu Changfeng" of the Lesotho Highlands Water Supply Project—began stepping forward, officially launching Sinohydro Bureau 3's TBM overseas traversal journey.

Having weathered many storms, the will grows stronger; the road ahead is still long after just crossing the mountain pass. Today, the footprints of the TBM team of Sinohydro Bureau 3's Manufacturing and Installation Company have spread across the Northeast, Northwest, Central, and Southern regions of the motherland, moving from domestic to international, from open-type to double-shield, from excavation diameters of 8.53 meters to 3.53 meters, from one machine tunneling to multiple machines operating simultaneously. The TBM team upholds the corporate spirit of "constant self-improvement and the courage to surpass," and is mustering all energy and striving hard, using practical actions to tell the TBM story of Sinohydro Bureau 3 well and using outstanding performance to build the TBM brand of Sinohydro Bureau 3 with all efforts.