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Our products have been widely used in urban subways, railway and highway tunnels, cross-sea and cross-river tunnels, municipal utility tunnels, hydraulic engineering projects, and other fields.
Our customers are located in major cities across China and also export to global markets including the Americas, Europe, Southeast Asia, and the Middle East. We have established strong partnerships with numerous large construction groups and tunnel-boring machine manufacturers.
The “Four World’s Firsts” have set a new global benchmark for high-speed railway tunnels. The tunnel boring machine (TBM) has successfully completed a single-heading tunnel crossing beneath the Yangtze River, spanning a distance of 11.3255 kilometers—the longest single-heading tunnel ever excavated worldwide. The tunnel utilizes the world’s largest-diameter high-speed railway TBM, the “Linghang,” with a maximum cutterhead diameter of 15.4 meters, creating an excavation cross-section of 186 square meters—equivalent to the height of a five-story building. The tunnel plunges as deep as 89 meters below the riverbed, enduring an ultra-high water pressure of 1.02 megapascals (equivalent to 10 atmospheres). This makes it the deepest and highest-pressure underwater tunnel in the Yangtze River basin. The project has also established a world record for high-speed railway tunnels in the 15-meter class, achieving a monthly advance rate of 718 meters—and averaging 600 meters per month. With its “strategic-level value” at its core, this project not only overcame world-class engineering challenges such as ultra-long single-heading tunneling, ultra-high water pressure, and complex geological conditions, but also achieved breakthroughs across the board in engineering technology, construction management, and ecological protection.
During construction, a record was set for the TBM’s daily advance of 21 meters and monthly advance of 395 meters in hard rock strata with an ultra-large diameter. Moreover, through industry-academia-research collaboration, the project successfully overcame the challenge of lacking prior experience in constructing ultra-large-diameter dual-mode shield tunnels, providing a benchmark for similar projects.
The construction environment is complex and the project’s difficulty ranks among the highest in China. According to the Zhuhai Municipal People’s Government: This project is an exceptionally challenging, ultra-large-diameter underwater shield tunnel project in China. The tunnel boring machine (TBM) must traverse a composite geological stratum that is soft above and hard below over a distance of more than 800 meters—a stretch that represents the longest bedrock section ever encountered in a Chinese underwater shield tunnel. At the same time, the TBM will pass very closely beneath numerous existing structures and must also go under two water supply pipelines serving Macao. The clearance between the top of the tunnel and the bottom of the pipelines is only 7.08 meters, making the construction highly risky.
Wen Yi Road (Zijin Port Interchange — Jingchang Avenue)
The 2,200-meter tunnel section using a shield machine needs to pass under several critical infrastructure facilities, including the Qiandao Lake water supply pipeline, the Hangzhou Ring Expressway, a high-pressure gas pipeline, and the subway express line tunnel. The northern tunnel runs within less than 10 meters horizontally from the airport express line and extends for a parallel distance of up to 1,200 meters. During construction, vibration and settlement isolation technologies were employed, ensuring that the settlement of the airport express line remained below 8 millimeters and thereby guaranteeing its safe operation.
Shanghai Rail Transit Metropolitan Line Airport Connecting Line Project
Leading smart construction technology: The “Jiyue” is equipped with ultra-large-diameter tunnel boring machine (TBM) synchronous jacking and segment assembly technology, enabling simultaneous excavation and segment installation—a “parallel” operation that reduces the average time per ring to just 85 minutes, boosting efficiency by nearly 30%. In Section 11, the “Hongpu” TBM has been deployed to implement an intelligent construction system for TBM tunnels, setting a new industry record for 14-meter-class TBMs with daily advances of 32 meters and monthly advances of 650 meters.
Highly challenging construction risk management: The project area traverses central districts including Minhang, Xuhui, and Pudong, requiring the tunnel to pass beneath existing lines such as Metro Line 12 and numerous critical buildings and structures. For instance, in Section 3, Shaft No. 2 is located adjacent to the elevated section of the Shanghai-Kunming High-Speed Railway; during TBM reception, there was a risk of water and sand inflow, so the underwater reception method was ultimately adopted to mitigate this risk. In Section 13, the tunnel section passing under the Pudong Airport terminal building has a buried depth exceeding 50 meters—the deepest TBM tunnel section ever constructed in Shanghai—and requires long-distance tunneling through sandy layers.
Hangzhou Zhijiang Road Water Pipeline Tunnel and Road Improvement Project
The geological conditions are complex and construction is highly challenging: The tunnel needs to pass through a variety of intricate strata, including weathered quartz sandstone and silty clayey silt. The strength of the hard rock exceeds that of ordinary concrete by more than three times, causing extreme wear on cutting tools. At the same time, the tunnel successfully achieved a tight-radius curve with a radius of just 650 meters, overcoming the significant technical challenges associated with constructing ultra-large-diameter shield tunnels. Additionally, it effectively addressed the risk of uplift during shield tunneling in areas with extremely shallow overburden.
The project features prominent green and立体 (three-dimensional) transportation characteristics: Upon completion, it will adopt a “four-lane双向 (two-way) road above ground plus four-lane双向 (two-way) road underground” configuration. The number of lanes on the ground-level roads will be reduced to widen the riverside scenic belt. In certain sections, sunken roads will be used to seamlessly connect parks with the Qiantang River. Meanwhile, the project integrates water pipeline corridors, simultaneously enhancing both the city’s water network and road network.
With an excavation diameter of 15.8 meters—equivalent to the height of a five-story building—it was the largest-diameter slurry shield tunneling machine in China at the time. The tunnel’s exceptionally long distance of 3,603 meters represents a rare project of its kind in China, and its construction difficulty ranks among the highest in the world. The construction area is located in the core district of Shenzhen, where old buildings are densely packed along the route. The tunnel directly passes beneath 28 existing old buildings and runs alongside 78 other structures, most of which have shallow foundations with poor resistance to settlement. Furthermore, the tunnel must pass through 11 fault fracture zones, with surrounding rock strength reaching as high as 173 megapascals. Additionally, the project involves continuous curves with small radii, while also needing to avoid sensitive areas such as subway lines and railway tracks—resulting in extremely high construction risks.
It is the world’s first large-diameter shield tunnel located in an area with an earthquake intensity of 8 degrees. It is also Guangdong Province’s first highway tunnel constructed using the shield method beneath the sea, and has been dubbed “the most challenging large-diameter shield project” in China. At its deepest point, the tunnel lies 98.5 meters below sea level, situated in a region experiencing high seismic intensity of magnitude 8. To overcome challenges such as nearly 100-meter-high water pressure and severe chloride corrosion, the tunneling machine had to bore through extremely hard granite strata with a compressive strength of up to 200 megapascals. The shield tunnel section successfully passed through a 135-meter-long fault zone thanks to advanced ground consolidation measures applied ahead of the tunnel face. During construction, the team set several remarkable records: 14 meters per shift, 24 meters per day, and 432 meters per month—breaking the previous record for domestically produced ultra-large-diameter slurry balance shield machines.
Wuhan Yangtze River Road-Rail Tunnel
World’s First Public-Rail Integrated Construction Model: This is the world’s first completed shield-tunnel crossing a river that integrates both road and rail transportation. It features a dual-tube, three-layer structure: the upper layer serves as a highway smoke-exhaust duct; the middle layer accommodates a six-lane双向 highway; and the lower layer houses the tracks of Metro Line 7, a shared evacuation passage for both road and rail users, and utility tunnels—all designed to achieve intensive resource utilization.
The construction faced enormous geological challenges: it was necessary to overcome the dual geological hurdles of the “diamond layer” and the “sticky rice cake” formation. The strata contain up to 70% quartz, resulting in extremely high hardness that led to the cumulative replacement of over 2,000 cutterheads during construction. At the same time, highly cohesive muddy siltstone posed another significant challenge, easily causing cutterhead clogging and mud cake buildup. To address this issue, the construction team adopted innovative methods such as injecting hydrogen peroxide.
Abundant Awards and Technological Achievements: The project has won numerous prestigious awards, including the National High-Quality Engineering Award and the FIIDC Outstanding Engineering Award. Its research achievements were honored with the Second Prize of the National Science and Technology Progress Award. During construction, the team developed several technical procedures, such as the "Normal-Pressure Cutterhead Replacement Operating Procedures," and the newly developed "First Reverse, Then Forward, and Finally Expansion" reverse construction method significantly reduced construction costs.
Nanjing Dinghuaimen Yangtze River Tunnel
Leading in design scale: Adopting the world’s first double-layer, multi-outlet X-shaped overall design, this tunnel features a dual-tube, double-deck, eight-lane structure that efficiently diverts traffic flow. At the time, it was the largest project of its kind in the world.
Extremely high construction difficulty: Dubbed a “world-class project located 70 meters beneath the riverbed,” it required crossing the Yangtze River’s embankment four times, with local overburden thickness as little as 9 meters. The tunnel had to pass through various geological strata, including soft soil and hard rock, with quartz content in the rock layers reaching as high as 65%. During construction, the water pressure reached up to 0.72 megapascals, and there were instances when only 3–4 meters could be excavated in a single day.
Independent technological innovation: The tunnel boring machines used in this project boasted numerous pioneering technologies both internationally and domestically—for example, retractable cutterheads and a cutter disc capable of extending by 100 millimeters. These innovations enabled the machine to achieve an unprecedented record of continuous excavation for 2,580 meters in sandy gravel strata without changing cutters. The related technologies have earned multiple invention patents.
Dalian Metro Line 5: Subway Tunnel Between Railway Station and Suoyuwan South Station
This project represents the world’s first large-diameter shield tunnel constructed in karst geology beneath the sea. The tunnel must traverse a 1,538-meter-long section characterized by highly developed karst features, where thousands of sinkholes of varying sizes are distributed, with the largest cavity reaching a height of 29.8 meters. At the same time, the tunnel must also contend with hard rock formations whose maximum compressive strength reaches 118 megapascals. Moreover, the tunnel faces a maximum hydrostatic head pressure of 0.5 megapascal—a high-pressure environment that poses significant challenges to the tunnel’s sealing and pressure-resistance capabilities. During shield tunneling, the tunnel will pass under several critical infrastructure facilities, including the Shugang Railway, Heizui Port, and Xianglu Reef Navigation Channel. Additionally, the surrounding area is marked by complex geological formations such as weathered zones and fault zones. It is essential not only to avoid any adverse impacts on these facilities during construction but also to address the difficulties in maintaining precise tunnel alignment caused by the uneven distribution of soft and hard strata.
Wuhan Sanyang Road Yangtze River Tunnel
World’s First Public-Rail Integrated Construction Model: This is the world’s first completed shield-tunnel crossing a river that integrates both road and rail transportation. It features a dual-tube, three-layer structure: the upper layer serves as a highway smoke-exhaust duct; the middle layer accommodates a six-lane双向 highway; and the lower layer houses the tracks of Metro Line 7, a shared evacuation passage for both road and rail users, and utility tunnels—all designed to achieve intensive resource utilization. The construction faced enormous geological challenges: it was necessary to overcome the dual geological hurdles of the “diamond layer” and the “rice cake dough” formation. The rock strata contain up to 70% quartz, making them exceptionally hard—resulting in over 2,000 cutter changes during construction. At the same time, highly cohesive mudstone-siltstone formations posed significant risks of cutter clogging and mud cake buildup. To address these issues, the construction team employed innovative methods such as injecting hydrogen peroxide. The project has reaped numerous awards and technological achievements: it has won multiple prestigious honors, including the National High-Quality Engineering Award and the FIIDC Outstanding Engineering Award. Its research outcomes were recognized with the Second Prize of the National Science and Technology Progress Award. During construction, the team developed several technical procedures, including the "Normal-Pressure Cutter-Change Operating Procedures," and the newly devised "First Reverse, Then Forward, Finally Expansion" reverse construction method, which significantly reduced construction costs.
