In recent years, China has built a lot of tunnels, among which the undersea tunnel is the most eye-catching. Today, let's take a look at a company that is also very strong in the field of shield tunneling (especially in the field of cross-river-sea tunnels) - Tunnel Co., Ltd. Shanghai Tunnel! And in the Shenzhen Mawan Cross-sea Passage, China Railway Tunnel Bureau and Shanghai Tunnel Co., Ltd. have already staged a competition on the same stage, let us enjoy the elegance of the subway army together.

Mawan Cross-sea Channel

The Mawan Cross-sea Passage (Moon Bay Avenue-Yanjiang Expressway) is arranged in a north-south direction, starting from the intersection of Mawan Avenue and Moon Bay Avenue in the south, connecting with the existing Mawan Avenue viaduct, crossing the Qianhai Bay waters to the north, and ending at Dachanwan Toll Station of Yanjiang Expressway and the intersection of Jinwan Avenue and Xixiang Avenue. The project passes through the two areas of Qianhai Mawan and Baoan Dachan Bay. The total length of the route is about 8.05 kilometers, of which the Qianhai section is 2.5 kilometers, the sea area is 1.1 kilometers, and the Dachan Bay section is 4.45 kilometers.

The Mawan sea-crossing passage is divided into two parts: surface road and underground road. The underground road is planned to be urban expressway, with 6 lanes in both directions, with a design speed of 80 km/h. The total length of the underground tunnel is 6,280 meters, of which the Qianhai land area is open-cut tunnel section. 820 meters, the shield tunnel section in the sea area is 2060 meters, and the open-cut tunnel section in the Dachan Bay land area is 3400 meters.

The construction tasks of the first tender section (Qianhai + sea area shield section) include: Qianhai section 2.4km (roads, tunnels, power tunnels, pipelines, etc.) + sea area single-hole shield (including 1 shield machine) + departure Wells and other projects. It was won by Shanghai Tunnel Engineering Co., Ltd., a subsidiary of Tunnel Co., Ltd., with a bid price of 3.807 billion yuan.

The construction tasks of the second tender section (sea single-hole shield + Bao'an section) include but are not limited to: Bao'an section 4.46km (roads, tunnels, bridges, integrated pipe corridors, pipelines, etc.) + sea section single-hole shield (including 1 set) Shield machine) + receiving well and other projects. It was won by the consortium of China Railway Tunnel Bureau Group Co., Ltd. with a winning bid price of 5.559 billion yuan.

This move also means that Shanghai Tunnel Co., Ltd. and China Railway Tunnel Bureau will compete in the ten-billion-billion-dollar cross-sea channel arena of Mawan!

Tunnel Shares Shanghai Tunnel: "Pengcheng"

Shanghai Tunnel Engineering Co., Ltd. is a company specializing in the construction of soft soil tunnels. It is also the first listed joint-stock company in China's construction industry and the first construction company in China to set up a post-doctoral workstation. Shanghai Tunnel has been insisting on independent innovation since the shield research and development test in Shanghai Tangqiao in 1958. It has accumulated rich experience in the field of super-large diameter shield tunnel construction, developed innovative achievements, and has become a pioneer in shield tunnel technology innovation. Its evolution process is as follows:

In August 1965, Shanghai Tunnel Engineering Company was established, becoming the earliest professional engineering construction unit in China to conduct shield tunnel testing and engineering application.

In May 1968, Shanghai Tunnel Department and Shanghai Tunnel Engineering Design Institute were merged into Shanghai Tunnel Engineering Company and renamed as Shanghai Tunnel Construction Company.

In April 1985, the Shanghai Tunnel Engineering Design Institute was restored, and the tunnel construction company was renamed Shanghai Tunnel Engineering Company.

In November 1993, it was restructured into Shanghai Tunnel Engineering Co., Ltd. (“Tunnel Shares”), and it was listed on the Shanghai Stock Exchange on January 28 of the following year, becoming the first Chinese construction company to go public.

In July 2014, Tunnel Co., Ltd. fully invested in Shanghai Tunnel Engineering Co., Ltd. Shanghai Tunnel Engineering Co., Ltd. began to engage in general contracting of construction and related supporting businesses.

The most powerful thing is that Tunnel Co., Ltd. is the only construction group in the world that has both tunnel construction and tunnel construction equipment manufacturing capabilities. Now it has grown into a comprehensive service provider of urban infrastructure construction and operation recognized in the global EPC market. Up to now, the total assets of Tunnel Co., Ltd. have exceeded 100 billion yuan, and the accumulated investment in infrastructure in the past three years has exceeded 120 billion yuan. Its business covers tunnels, rail transit, roads and bridges, construction and real estate, water conservancy and water affairs, energy, underground space, major equipment, green Materials, digital business, construction finance and other fields.

On October 30, 2021, the "Pengcheng" shield machine on the left line of the Mawan Cross-Sea Passage Project successfully started.

The construction content of Section 1 of Mawan Cross-Sea Passage undertaken by Shanghai Tunnel Co., Ltd. mainly includes an open-cut tunnel with a length of 820m in the Qianhai section and a single-hole super-diameter shield tunnel with a length of 2060m in the sea section (left line). The sea section adopts Herrenknecht knives. The "Pengcheng" construction of the mud-water balance shield with a disk diameter of 15.55m.

Construction difficulties: "Pengcheng" will face the construction challenges of excavation in composite strata such as full-section hard rock, upper soft and lower hard strata, and soft soil strata.

The total length of the full-section hard rock section is over 700m, and the maximum strength is as high as 193MPa, which greatly tests the rock-breaking ability of the cutter head. At the same time, it may also occur that the cutter needs to be replaced frequently due to wear. The upper part of the structure is cut too fast, which causes the overall posture of the shield machine to rise, which in turn causes problems such as dislocation and deformation of the tunnel segments; the soft soil layer is likely to cause mud on the cutter head, so that the cutter head cannot be effectively driven by being wrapped in mud.

Of course, the "Pengcheng" is also a stunt. "Pengcheng" has a total weight of 3700t and a total length of 105m, of which the length of the main engine is 15.6m, the cutting diameter of the cutter head is 15.55m, and the minimum turning radius is 600m. The main drive core consists of 16 variable frequency motors with a total power of 5600kW, a maximum torque of 41583kNm, a maximum thrust of 199504kN, and a maximum propulsion speed of 50mm/min. It is a veritable "super giant".

Let's take a look at some of the dazzling achievements of Shanghai Tunnel in the past:

The first cross-river tunnel in China built by Shanghai Tunnel Shanghai Tunnel Co., Ltd. - Shanghai Dapu Road Tunnel, created the era of "holes in the tofu", that is, the era of Chinese shield tunneling. It has created a new situation in China's soft soil tunnel technology. At the same time, the deficiencies and problems of leakage, subsidence and payment of sand and other aspects found in the project have also become the main direction of Shanghai tunnel construction since then, and will be continuously improved. Its tunnel segment has an outer diameter of 10.1 meters, which has also become the defining standard for large tunnels in the industry.

The Shanghai Shangzhong Road Cross-River Tunnel (the largest diameter cross-river road tunnel in the world at the time of construction) was undertaken. This tunnel is the first soft soil tunnel project in China to be constructed with a shield machine with a diameter of more than 14 meters. A key node project of Jiang. The construction of this project has opened a new chapter in the construction of the "super-large diameter" mud-water-gas balance shield.

During the construction of the Yangtze River Tunnel on Sanyang Road in Wuhan, the Shanghai Tunnel has overcome the world-class problems of the most complex "diamond layer" and "rice cake layer" in the river. At the same time, the tunnel also became the first super-diameter cross-river tunnel in the middle and upper reaches of the Yangtze River, the largest diameter shield tunnel in China at that time, and the world's first shield tunnel constructed by a combination of road and rail.

The completed Zhuhai Hengqin Tunnel is the largest undersea tunnel in South China, and it is also a super-large diameter composite stratum shield tunnel in the domestic waters. The tunnel is faced with the problems of "soft upper and lower hard" composite strata, lots of riprap, and great influence of seawater on mud. Targeted measures such as entering the cabin and changing tools. The penetration of the Hengqin Tunnel means that the key technologies for the design and construction of the super-diameter shield tunnel in the composite stratum of the South China Sea area have been conquered.

During the construction of the North Cross Passage, the Shanghai Tunnel achieved a breakthrough of a 15.59-meter super-diameter shield tunnel passing through 6 rail transit tunnels in operation and 92 buildings in a row.

The Shanghai Yangtze River Tunnel project constructed by Tunnel Co., Ltd. was constructed with two mud-water-gas balance shields with a diameter of 15.43m. It was the largest shield tunnel in the world at that time, and it was also well-received by the world for its long, large and deep characteristics. Attention. At the same time, it set three world records of the largest shield diameter, the longest single excavation distance and the deepest burial depth at that time.

The Qianjiang Tunnel in Hangzhou, Zhejiang Province is the first super-diameter shield tunneling project in China with BOT mode. During the construction process, Tunnel Co., Ltd. successfully advanced the super-diameter shield machine "Qianjiang Tongtai" with a diameter of 15.43 meters to cross the earth embankment of the Ming Dynasty four times. The foundation Qianjiang embankment overcomes the century-level problem of constructing large-scale expressway tunnels across the river under the special hydrological conditions of the Qiantang River.

China Railway Tunnel Bureau: "Mawan"

The total length of the shield section of the Mawan Cross-Sea Corridor 2 bid project undertaken by China Railway Tunnel Bureau is 2,063 meters, of which the sea section is 1,100 meters. A domestic shield machine "Mawan" tailored for the project was adopted, with a diameter of 15.53 meters, and the excavation section is 6 times that of the conventional subway shield machine. It is also the largest diameter shield machine used in underwater tunnel construction in China.

The uneven top and bottom hard strata encountered by the "Mawan" accounted for more than 50%, and the maximum rock strength reached 193 MPa. The repeated changes in the stratum brought severe challenges to the project. During the construction, the builders of the China Railway Tunnel Bureau rely on the big data platform of the smart shield TBM project to realize real-time intelligent monitoring and automatic early warning of the excavation parameters. Using digital Beidou positioning, information-based BIM, 5D and intelligent monitoring and other technologies to fully perceive the surrounding environment of the project, changing the traditional methods of manual supervision and lofting, the construction accuracy and monitoring efficiency have been greatly improved.

Since the launch of the "Mawan" shield machine on July 15, 2021, the single-day excavation exceeded 10 meters on October 28, 2021, and the single-month excavation exceeded 150 meters in November. The current accumulated excavation has exceeded 740 meters.

2021 is the peak period for the simultaneous construction of cut-and-cover tunnels and shield tunnels in the Mawan Cross-Sea Passage Project. The "Mawan" large shield of China Railway Tunnel Bureau has maintained efficient excavation since its inception, with an annual output value of 658 million 120% of the annual plan is completed. Polishing the gold-lettered signboard of China Railway Tunnel Bureau's large shield construction, and making new contributions for China Railway Tunnel Bureau to lead the construction technology of cross-river-cross-sea tunnels and firmly occupy the leading position in the large shield industry!

Let’s take a look at other achievements of China Railway Tunnel Bureau:

It has successfully built the Wuhan Yangtze River Tunnel, the "First Tunnel of the Yangtze River in Ten Thousand Miles", which has become the first Yangtze River highway tunnel to be constructed and penetrated first in China.

Xiamen Xiang'an Subsea Tunnel has overcome more than 30 scientific research and experimental projects and successfully passed through the seabed weathered deep trough 12 times. It is not only the first large-section subsea tunnel in mainland my country, but also the first subsea tunnel designed by domestic experts. The world's first large-section drill-and-blast construction submarine road tunnel.

The construction of the Harbin Rail Transit Line 2 Phase I Cross-river Tunnel between Wubiao Taiyangdao Station and People's Square Station successfully crossed the 1.2-kilometer-wide main river of the Songhua River at one time, creating the first tunnel construction in China to cross the Songhua River. precedent.

Qingdao Jiaozhou Bay Submarine Tunnel, the second subsea tunnel in the mainland and the third longest subsea highway tunnel in the world, was designed and constructed by China Railway Tunnel Bureau Group. A total of 18 geological faults have been passed through, and the construction is very difficult. It is the first time in the history of China's submarine tunnel construction.

The Shiziyang Tunnel of the Guangzhou-Shenzhen-Hong Kong high-speed railway was the first railway underwater shield tunnel in China, and it was also the underwater railway tunnel with the longest mileage and the highest construction standard in my country at that time. A number of technical gaps in the construction of balanced shield machines. After many years, China Railway Tunnel Bureau Group has undertaken the construction of the world's largest underwater railway shield tunnel - the Shiziyang Tunnel of the Foguang Intercity Railway, which is currently the largest diameter railway shield tunnel under construction in China; The lower shield tunnel is also the first project in China to use earth pressure-slurry dual-mode shield tunneling in the field of large-diameter shield tunnels.

The Shenzhen-Zhongshan Corridor is the only direct highway connection between the three major free trade zones in the Guangdong-Hong Kong-Macao Greater Bay Area and the two major urban agglomerations of "Shenguanhui" and "Zhuzhongjiang". After completion, the driving time from Shenzhen to Zhongshan will be shortened from the current 2.5 hours to 20 minutes. As an important part of the channel project, the builders of the China Railway Tunnel Bureau reclaimed the East Artificial Island in Lingdingyang Sea, a land area equivalent to 48 standard football fields. After completion, it will become the first underwater interchange on domestic expressways, truly realizing rapid Convenient transportation transformation and interconnection between cities.

The Pearl River Mouth Tunnel Project of the Deep River Railway (the world's largest hydraulic tunnel) is a key control project of the Deep River Railway. The total length of the tunnel is 13.69 kilometers. The China Railway Tunnel Bureau has undertaken the construction task of 9,175 meters, including 5,490 meters of mining method tunnels and 2,930 meters of shield method tunnels. 755 meters of open-cut tunnels and 1,160 meters of inclined shafts. The construction methods in the tender section are diverse, and the hydrogeological conditions are complex. The shield section is constructed with a super-diameter shield with a diameter of 13.32 meters. The single head runs down the Pearl River for a long distance. The highest uniaxial compressive strength of the rock reaches 200Mpa, and the water pressure is the highest in the world.

In August 2020, the Shantou Bay Tunnel, the world's first bay tunnel that passed through the 8-degree earthquake intensity area, was constructed by China Railway Tunnel Bureau. The project adopts two super-large shield tunnels with a diameter of more than 15 meters in the same direction. Qian Qihu, Zhou Fulin, Nie Jianguo, Du Yanliang, Niu Xinqiang, Zheng Jianlong, Ren Huiqi, Xie Xianqi, Li Shucai, 9 academicians of the Chinese Academy of Engineering, Yan Jinxiu, chairman of the International Tunnel Association and other hundreds of experts pointed out that the China Railway Tunnel Bureau is a world-class challenging project in Shantou Bay The successful practice of the tunnel shows that my country's shield tunnel technology has reached the international leading level, which not only enriches my country's experience in the construction of tunnels across the river and the sea, but also provides technical support for the century dream of my country's three major strait tunnels.

This time, the two underground ace iron armies who cross the river and the sea will face off against the ten billion arena of the Mawan Cross-sea Passage. Who do you prefer? Editor/Sang Xiaomei