July 24

As the super-large-diameter shield tunneling machine with a diameter of 17.5 meters

the cutterhead of "Shanhe" was successfully lowered into the shaft

invested and constructed by Jinan Urban Construction Group

and undertaken by China Railway 14th Bureau Group

the Yellow River Crossing Tunnel on Huanggang Road in Jinan

the assembly of the shield tunneling machine has been basically completed

marking that the "Shanhe" shield tunneling machine is about to enter the commissioning stage

the launch of the shield tunneling for the world's largest-diameter underwater shield tunnel

has entered the "countdown"

01. Experts jointly witness the "Qilin" in place

Site of the cutterhead lowering ceremony

He Chuan, academician of the Chinese Academy of Engineering and vice president of Southwest Jiaotong University; Xu Weimin, Party secretary and chairman of Jinan Urban Construction Group; Zhou Changjin, general manager of China Railway 14th Bureau; Yuan Dajun, chief expert of the National 973 Program and professor at Beijing Jiaotong University; Li Liping, National Science Fund for Distinguished Young Scholars recipient and dean of the Qilu Transportation College of Shandong University; Zhang Liang, Party secretary and chairman of Shanghai Municipal Engineering Design Institute (Group) Co., Ltd.; and others jointly participated in the event and witnessed on site the lowering of the cutterhead of the "Shanhe" shield tunneling machine.

In his speech, Zhou Changjin stated that China Railway 14th Bureau will deepen refined project management and technological innovation, strictly control safety and quality, strengthen the connection and transition of processes, and, with a high sense of responsibility and mission, build the Yellow River Crossing Tunnel on Huanggang Road in Jinan into a premium, safe, green, innovative, and clean project that can stand the test of history.

During the event, the expert team also visited the smart exhibition hall and construction site of the Yellow River Crossing Tunnel on Huanggang Road in Jinan, and learned in detail about the project overview, construction techniques, and the equipment of the "Shanhe" shield tunneling machine.

02. A steel giant six stories tall precisely "merges"

The "Shanhe" shield tunneling machine is the largest-diameter slurry balance shield tunneling machine currently under construction in the world, with a maximum excavation diameter of 17.5 meters. The cutterhead lowered into the shaft this time is assembled from one central block and four side blocks, weighing about 387 tons. The lifting and lowering of the cutterhead is the most important part of the entire lifting and assembly stage of the shield tunneling machine, and it is also the most difficult and highest-risk procedure.

Lifting

Standing

Turning in the air

Precise merging

On the morning of that day, the cutterhead of the "Shanhe" shield tunneling machine, painted with the auspicious beast Qilin pattern, slowly "stood up" from the ground with the assistance of two crawler cranes with lifting capacities of 800 tons and 400 tons. After completing an "air turn," it accurately descended to the predetermined position in the launch shaft and precisely "merged" with the shield tunneling machine.

03. "Shanhe" is about to begin its river-crossing journey

The Yellow River Crossing Tunnel on Huanggang Road in Jinan has a total length of about 5,755 meters, with a tunnel length of about 4,762 meters, of which the shield-driven section is 3,290 meters. It adopts a single-tube upper-and-lower double-deck shield configuration, with dual three-lane carriageways in both directions and a design speed of 60 kilometers per hour. The project is characterized by being large, difficult, high-risk, and complex.

The "Shanhe" shield tunneling machine will launch from the working shaft on the north bank and bore southward, crossing over a long distance through composite strata such as silty clay, calcareous concretions, and cemented sand layers, before reaching the working shaft on the south side, where it will be dismantled and lifted out.

Large

Super-large-diameter shield tunneling, with a large excavation cross-section and a long single-head continuous boring distance;

Difficult

Dense underground risk sources and a complex environment, with many factors controlling the boring;

High

Long-distance crossing through composite strata of silty clay and calcareous concretions, with high construction risk;

Many

Many internal structure procedures and a large volume, constructed in parallel with shield boring, making cross-coordination highly difficult.

04. "Qilin" possesses multiple special skills

The project customized the "Shanhe" shield tunneling machine, equipped with advanced equipment such as a pressurized composite cutterhead, a telescopic main drive, and a telescopic camera in the excavation chamber. Its assembly level has reached the world's advanced level.

In addition, the shield tunneling machine is equipped with an intelligent equipment system known as the "five senses and one brain," including advanced geological forecasting, stratum interface identification, gas environment monitoring, disc cutter wear monitoring, synchronous grouting detection, and an auxiliary decision-making support system. This is like installing "eyes," "ears," and a "nose" on the shield tunneling machine, comprehensively enhancing the intelligent perception capability of the "Shanhe" shield tunneling machine. Through intelligent decision-making by the "brain center," it can greatly reduce the safety risks of shield construction and more effectively adapt to the complex and changeable construction environment and high-standard technical requirements.

05. Multiple measures help the "Qilin" go underground

To ensure the smooth "merging" of the "Shanhe" shield tunneling machine, the project team made scientific deployments and advance plans, continuously integrated resources and optimized allocations, formulated a detailed plan for lifting and lowering the cutterhead into the shaft, and conducted multiple lifting simulations. They also carried out detailed lifting safety training and technical briefings for management personnel at all levels and frontline construction workers to ensure the precise docking of the cutterhead and the shield body.

After the shield tunneling machine cutterhead is lowered into the shaft, the project department will carry out construction work such as moving the shield body forward, the shield tail, the segment erector, connecting pipelines, synchronous commissioning, and negative ring assembly, laying a solid foundation for the subsequent launch of the shield.

The Yellow River Crossing Tunnel on Huanggang Road in Jinan is one of the major north-south passages across the Yellow River. Once completed, it will help achieve interconnection between Jinan's main urban area and the Starting Area for the Conversion of Old and New Growth Drivers, strongly accelerate the comprehensive construction of the Starting Area, promote Jinan's transition from the "Daming Lake era" to the "Yellow River era," and provide strong support for the ecological protection and high-quality development of the Yellow River Basin.