On July 9, after 33 hours of continuous pouring, the final batch of concrete for the anchorage base slab of the Shiziyang Bridge, a controlling works of the Shiziyang Channel project, was completed at 20:00 on July 8, marking the safe completion of the base of the world's largest anchorage foundation pit. The next step will soon move into the core-filling construction stage.

The total weight of the west anchorage of the Shiziyang Bridge is comparable to 17 aircraft carriers.

At 2 a.m. on July 8, the construction site of the west anchorage of the Shiziyang Bridge, located on Shazai Island, Huangge Town, Nansha District, Guangzhou, was still brightly lit. On-site technical personnel were carefully inspecting every truck of concrete, and pouring was permitted only after the measured placing temperature was below 28°C. Construction workers carried out operations in an orderly manner according to grid-based fixed posts and responsibilities, and conducted standardized vibration to ensure uniform, high-quality concrete.

As a key controlling works of the Shiziyang Channel project, the Shiziyang Bridge adopts a double-deck steel truss suspension bridge scheme with a main span of 2,180 meters, crossing the river in a single span. It is one of the bridges with the greatest technical difficulty and the most complex construction technology in China and even the world. Once completed, it will create five world records for double-deck suspension bridges: main span length, number of lanes, main tower height, anchorage foundation, and main cable scale.

As the load-bearing component that fixes the main cable strands of a suspension bridge, the anchorage consists of a foundation and an anchorage body. It is crucial to the bridge's century-long safety and durability and is the bridge's "stabilizing anchor." The Shiziyang Bridge has two anchorages, east and west, constructed by Poly Changda and CCCC Second Highway Engineering Co., Ltd. respectively. The circular gravity anchorage scheme is adopted, featuring a large structural volume and a long construction period. The west anchorage foundation pit has a diameter of 130 meters, with a total concrete pouring volume of up to 550,000 cubic meters and a weight of about 1.4 million tons, equivalent to 17 large aircraft carriers. The anchorage foundation pit base slab is 6 meters thick and is poured in three layers. Each layer is divided according to a nine-grid layout, requiring a total of 27 pours.

"The anchorage base slab construction of the Shiziyang Bridge faces a complex environment, a large concrete volume per pour, heavy resource allocation tasks, and difficult quality control. Facing a series of challenges, the project construction team pooled collective wisdom, repeatedly demonstrated and verified the plans, and adopted effective refined construction measures. The anchorage foundation has formed an overall closed reinforced concrete structure, effectively controlling the construction risks of foundation pit inrush and base slab uplift caused by the rising water level of the Pearl River during typhoon and flood seasons, ensuring the structural safety of the anchorage, and laying a solid foundation for the safe, high-quality, and efficient advancement of subsequent engineering construction."

Intelligent temperature control technology solves the *** challenge of mass concrete.

The Shiziyang Bridge is located in a coastal water-rich area. Affected by high summer temperatures and abundant rain, quality control of impermeability and crack resistance of the base slab mass concrete is particularly difficult.

During construction, faced with challenges such as large pouring volume and long duration per pour, high hydration heat of the base slab mass concrete, and large shrinkage deformation of the oversized base slab, the project construction team innovatively adopted "dual-admixture technology" and a composite high-performance expansive agent, successfully producing high-quality concrete with low temperature rise, low shrinkage, and high crack resistance, thus solving the cracking problem at the source.

To improve construction quality, on the one hand, the project construction team built a digital management platform and independently developed an automatic calculation and ice-water system. Based on real-time ambient temperature and raw material temperature monitoring data, it automatically controls the amount of ice and ice water added at the mixing station, strictly controlling the placing temperature of every cubic meter of concrete below 28°C. On the other hand, it innovatively developed an intelligent temperature control system for mass concrete. By embedding a series of temperature-measuring components, it automatically and wirelessly senses temperature changes and automatically controls the flow rate and temperature of circulating cooling water, achieving intelligent feedback control of mass concrete temperature.

Through a series of refined management and technological innovations, the project construction team achieved a dual improvement in safety and efficiency of anchorage base slab construction and effectively ensured construction quality. From the implementation results, the anchorage base slab concrete shows no cracking or seepage, providing an important guarantee for the high-quality construction of the Shiziyang Bridge.

The successful completion of the anchorage base slab construction marks that the main bridge construction of the Shiziyang Channel project has entered a new stage. At present, the main bridge construction of the project has fully entered the main tower column construction stage, and the manufacturing of the main tower steel shell has entered the stage of mass production.

The Shiziyang Channel is another super project in the Guangdong-Hong Kong-Macao Greater Bay Area after the Hong Kong-Zhuhai-Macao Bridge and the Shenzhen-Zhongshan Link. It is an east-west trunk channel that horizontally connects the three major metropolitan areas of the Guangdong-Hong Kong-Macao Greater Bay Area and radiates to the east and west wings, and an important component of the national coastal major corridor. Once completed, it will open up a new important channel for the integrated development of the east and west banks of the Pearl River Estuary, and is of great significance for promoting the integrated high-quality development of the Pearl River Estuary in the Greater Bay Area and building the 100-kilometer "Golden Inner Bay" around the Pearl River Estuary.