On July 24, as the cutterhead of the 17.5-meter super-large-diameter shield machine "Shanhe" was successfully lowered into the shaft, the assembly of the shield machine for the Huanggang Road Yellow River Crossing Tunnel in Jinan was basically completed, and it is about to enter the commissioning stage.

The Huanggang Road Yellow River Crossing Tunnel project in Jinan is located in Tianqiao District and the Starting Area of Jinan, starting about 150 meters south of the intersection of Lanxiang Middle Road and Huanggang Road, and running northward successively beneath Erhuan North Road, the Ring Expressway (Jiguang Expressway), the south bank levee, the Yellow River, the north bank levee, and the grit chamber of a Class I water source protection area, connecting with the G309 interchange under construction. The total length is about 5,755 meters, with a tunnel length of about 4,762 meters, of which the shield-driven section is 3,290 meters long with an excavation diameter of 17.5 meters. It adopts a single-tube double-deck shield configuration with three lanes in each direction and a design speed of 60 km/h.

On the morning of that day, the cutterhead of the "Shanhe" shield machine, painted with the pattern of the auspicious beast Qilin, 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 "airborne rotation," it was accurately lowered to the predetermined position in the launch shaft and precisely "merged" with the shield machine.

It is understood that the "Shanhe" shield machine is currently the world's largest-diameter slurry shield machine under construction, with a total length of 163 meters and a weight of 5,200 tons. Its cutterhead is assembled from one center block and four edge blocks, weighing about 387 tons. According to reports, the lifting and lowering of the cutterhead into the shaft is the most important part of the entire lifting and assembly stage of the shield machine, and also the most difficult and highest-risk procedure.

Since the "Shanhe" shield machine passed acceptance and rolled off the production line in Jinan on May 19 this year, it took 3 days to complete the disassembly of the cutterhead and 40 days to complete the disassembly of the shield machine. On May 24, the first block of the shield machine was successfully transported to the construction site of the Huanggang Road Yellow River Crossing Tunnel in Jinan. On May 27, the center block of the cutterhead, with a diameter of 9.5 meters and a weight of 195 tons, also arrived smoothly.

On June 11, the first component of the shield machine—No. 1 trailer, weighing 510 tons and about 30 meters long—was successfully lifted and lowered into the shaft, officially kicking off the shaft-lowering and assembly of the world's largest-diameter slurry shield machine under construction. On July 12, the main drive and No. 4 trailer of the "Shanhe" shield machine were successfully lowered into the shaft at the same time, bringing it one step closer to the shield launch milestone.

The Huanggang Road Yellow River Crossing Tunnel in Jinan adopts a design with a shield outer diameter of 16.8 meters and a single-tube double-deck configuration. Compared with conventional tunnels, a single tube solves the problem of two-way vehicle traffic while saving urban underground space and about 15% of investment. The 4.2-meter clear height can meet the requirements of buses, firefighting, management, and rescue, greatly improving the tunnel's traffic capacity.

According to reports, in order to ensure the smooth "merging" of the "Shanhe" shield machine, the project team made scientific deployments and advanced planning, continuously integrated resources and optimized configurations, 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.

The final assembly of the "Shanhe" shield machine has reached the world's advanced level. It is equipped with advanced equipment such as a pressurized composite cutterhead, a telescopic main drive, and a telescopic camera in the excavation chamber, and carries an intelligent equipment system known as "five senses and one brain," including advanced geological forecasting, stratum interface identification, gas environment monitoring, cutter wear detection devices, synchronous grouting detection, and an auxiliary decision-making support system.

After the shield machine's cutterhead is lowered into the shaft, we 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 shield launch. The "Shanhe" shield machine will launch from the working shaft on the north bank and bore southward, with a single-head tunneling distance of 3,290 meters, 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 to be dismantled and lifted out.

The Huanggang Road Yellow River Crossing Tunnel project in Jinan is one of the major north-south corridors across the Yellow River. Once completed, it will help achieve interconnectivity between Jinan's main urban area and the Old and New Growth Drivers Conversion Starting Area, 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.