In June 2026, the "Zhaosu" full-face hard rock tunnel boring machine (TBM) precisely reached its designated stopping point within the pilot tunnel at the entrance of the West Tianshan Extra-Long Tunnel on the G219 Zhaosu-Wensu Highway. This highway tunnel, featuring the world's deepest burial depth for a large cross-section and the world's first first-class highway tunnel to directly traverse a glacier, finally witnessed the historic moment of the pilot tunnel's breakthrough. Simultaneously, the "Zhaosu" and its counterpart, the "Wensu," both domestically produced TBMs, advanced towards each other, delivering impressive results that rewrite industry records.

World-Class Challenge: Traversing the "Geological Forbidden Zone" of the Tianshan Glacier Core

The West Tianshan Extra-Long Tunnel, with a total length of 15.7 kilometers, is the core controlling project of the entire G219 Zhaosu-Wensu Highway. This tunnel boasts several "industry firsts": the world's deepest large-cross-section highway tunnel, the world's first first-class highway tunnel to directly traverse a glacier, and also the highway tunnel in China that crosses the largest active fault zone.

The harshness of the construction environment is extremely rare in the history of tunnel engineering:

Maximum burial depth of 2,365 meters (some sources state 2,380 meters), with over 11.96 kilometers of the tunnel length buried deeper than 1,000 meters

Over 70% of the construction area is covered by glacial strata

Crosses the 370-meter-long F1 active fault zone, the largest of its kind in China

Average daily water inflow reaches 28,000 cubic meters

Internal tunnel temperature reaches 41°C, compounded by extreme challenges such as severe rock bursts and large deformation of surrounding rock

"High burial depth, high rock burst potential, high water inflow, high weathering" — these "three highs and one strong" adverse geological conditions have made the West Tianshan Tunnel a globally recognized "tough nut to crack" in the tunnel engineering community.

Five Core Technologies: How the "Zhaosu" Became a "National Heavyweight Equipment"

To conquer this "geological forbidden zone," CCCC Tianhe Mechanical Equipment Manufacturing Co., Ltd. custom-designed the "Zhaosu" TBM for the West Tianshan project, featuring an excavation diameter of 8.83 meters, a total machine length of 237 meters (some sources state 235 meters), and a total weight of 1,500 tons. According to Chen Zhenpeng, Chief Designer of the Tunneling Machine Institute at CCCC Tianhe Design Institute, the "Zhaosu" is currently the open-type TBM with the largest excavation diameter and leading comprehensive performance among projects under construction in the Tianshan Mountains, a true domestic "national heavyweight equipment."

The five core self-developed technologies integrated into the "Zhaosu" form a complete technical matrix for addressing extreme geology:

(I) Gradient Alloy Cutter Technology

By optimizing cutter material and structural design, cutter lifespan is increased by 62% and cutter change frequency is reduced by 52%, significantly shortening downtime for maintenance and providing core support for long-distance continuous excavation.

(II) CFC High-Precision Advanced Water Detection System

This system can detect hydrological conditions up to 50 meters ahead, confidently handling extreme water inflow scenarios of up to 130,000 cubic meters per day. During excavation, the tunnel encountered multiple instances of glacial groundwater inrush triggered by marble rock layers, with a maximum daily water inflow of 25,000 cubic meters. The advanced water detection system provided crucial support for the construction team to map out the full strata data in advance.

(III) Microseismic Rock Burst Real-Time Warning Device

This device provides 24/7 coverage over the 3,000-meter high rock burst risk zone, allowing for early avoidance of collapse and impact risks. In the construction environment of the West Tianshan, characterized by frequent and severe rock bursts, this warning system serves as a core defense line for ensuring construction safety.

(IV) Multi-Level Collaborative Grouting System

Stabilizes loose surrounding rock in deep-buried tunnels, eliminating the risk of tunnel instability.

(V) High-Torque, High-Power Cutterhead Drive

The wear resistance of the cutters reaches 1.43 times that of conventional models, ensuring sustained and efficient rock-breaking capability in extremely hard rock strata such as 250 MPa ultra-hard granite.

Furthermore, the "Zhaosu" features a pioneering "open-type + single shield" dual-mode tunneling system, enabling rapid and intelligent switching between 250 MPa ultra-hard granite and fractured soft rock strata. The concurrently deployed, domestically pioneered lightweight steel segment support process has completely resolved the industry pain point of excavation collapse in altered rock strata.

Data Speaks: The "Acceleration" Rewriting Industry Records

Technological breakthroughs have directly translated into engineering achievements:

The world record set by the "Wensu" for large-diameter TBM tunneling at great depth, coupled with the stable high production of the "Zhaosu," jointly demonstrates that both domestically produced TBMs have reached internationally leading levels.

More critically, the results of tackling engineering difficulties include:

Safely penetrating the 370-meter-long F1 active fault zone, the largest in China, in just 7 months

Steadily handling an average daily water inflow of 28,000 cubic meters

Withstanding severe rock bursts and harsh conditions with high ground temperatures of 41°C inside the tunnel

Successfully completing excavation through the extremely challenging 2,365-meter ultra-deep section

Multiple construction innovations have been granted national invention patents and construction method certifications.

From "Tianshan Model" to "China Solution"

The Strategic Value of the Pilot Tunnel as a "Pioneer"

The West Tianshan Tunnel adopts a "dual main tunnels + left pilot tunnel" three-tunnel parallel construction scheme — the main tunnels use the drill-and-blast method, while the pilot tunnel relies on TBM mechanized excavation. Serving as a leading auxiliary roadway, the pilot tunnel plays a key role in geological exploration and route optimization, acting as the "pioneer" for constructing long, large tunnels in complex geology.

Leveraging the advanced geological detection system carried by the "Zhaosu," the construction unit comprehensively mapped the strata conditions along the entire tunnel alignment, accumulating detailed geological reference data for the main tunnel construction. This complete geological reference plan significantly reduces the unknown risks associated with the drill-and-blast method in the main tunnels.

Breaking Import Dependence, Exporting "China Standards"

The successful completion of this pilot tunnel excavation task fully proves that domestically produced high-end tunneling equipment is fully capable of construction in glacial and ultra-deep composite geological conditions, and will provide mature, complete equipment solutions for similar extreme-condition tunnel projects in China.

From "introduction and absorption" to "independent development," and then to "technology export," the success of the "Zhaosu" marks that China's tunnel boring equipment has reached the forefront of the global industrial chain.

Reshaping Xinjiang's Transportation Landscape

The West Tianshan Tunnel is a key project within the national highway network. Upon completion, the driving distance from Yining to Aksu will be significantly reduced from 1,710 kilometers to 445 kilometers, opening a new fast passage across the Tianshan Mountains and greatly optimizing traffic efficiency in the western regional road network of Xinjiang.

Technological Replicability

The five core technologies and the steel segment synchronous assembly process validated by the "Zhaosu" have now been implemented and reused in multiple tunnel projects across China. All three TBMs for the G219 National Highway West Tianshan project were supplied by CCCC Tianhe. The "Wenquan" TBM, deployed for the construction of the 9,300-meter pilot tunnel of the Mosun Mountain on the Wen-Huo Highway, has also achieved remarkable results.

Compared to traditional drill-and-blast construction, the TBM achieves an average daily advance of about 20 meters, improving construction efficiency by more than four times.

From the 370-meter active fault zone to the world-class 2,380-meter ultra-deep burial, from an average daily water inflow of 28,000 cubic meters to high ground temperatures of 41°C and severe rock bursts — the "Zhaosu" has, over two years, completed an "ultimate test" for domestically produced high-end equipment deep within the Tianshan Mountains.

This is not merely the victory of a single TBM. From the "open-type + single shield" dual-mode intelligent switching, to the gradient alloy cutter technology increasing cutter lifespan by 62%; from the CFC advanced water detection system to the microseismic rock burst real-time warning — the integrated breakthrough of five core self-developed technologies signifies that China has formed a complete independent technological system in the field of extreme geological tunnel boring equipment.

As the "Zhaosu" precisely reached its designated stopping point, history was written for domestically produced high-end tunneling equipment conquering glacial and ultra-deep composite geology. "National Heavyweight Equipment" is no longer just a title; it is every solid meter of advance through the ice core of the Tianshan Mountains.