China News Service, Dongguan, October 8 (Reporter Cai Minjie) The core hub project of the Guangdong-Hong Kong-Macao Greater Bay Area - the Shiziyang Channel Shiziyang Bridge catwalk surface network laying began on the 8th, building a solid working platform for the subsequent erection of the super-large main cable. The catwalk has a single width of 6.26 meters, making it the widest suspension bridge construction catwalk currently under construction in the world.
The world's widest catwalk is now open for installation. Photo courtesy of Guangdong Communications Group
The Shiziyang Corridor is another super-large cross-river passage project in the Greater Bay Area after the Hong Kong-Zhuhai-Macao Bridge and the Shenzhen-Zhongshan Corridor. It is about 35 kilometers long and connects Nansha District of Guangzhou City and Humen and Shatian Towns of Dongguan City. The main project consists of the main cross-river bridge Shiziyang Bridge and the land lead projects on both sides. Once completed, it will promote the integrated development of the urban agglomeration in the Guangdong-Hong Kong-Macao Greater Bay Area.
As a full-line control project, the Shiziyang Bridge is a double-deck steel truss suspension bridge with a main span of 2,180 meters. It has set the world's first five double-deck suspension bridges in terms of "main span span, number of lanes, main tower height, anchorage foundation, and main cable diameter."
The catwalk is a high-altitude temporary working platform for superstructure construction such as the main cable erection of the Shiziyang Bridge. It is called the "aerial lifeline" of the super project and is divided into two sections, the upstream and downstream sections.
In view of world-class construction problems such as the 2,180-meter ultra-large span of the Shiziyang Bridge, the frequent typhoons in the Pearl River Estuary, and the complex high-altitude wind field, the project team carried out a large number of special scientific research and built a world-class catwalk with a single width of 6.26 meters, which is more than The width of the conventional long-span suspension bridge catwalk has been increased by about 50%, which can meet the multi-process parallel operation requirements of the ultra-large main cable weighing 43,000 tons and about 1.5 meters in diameter, expand the high-altitude construction operation surface, and improve the simultaneous construction capabilities and operation safety of multiple teams.
Kuang Yicheng, the chief engineer of the T9 standard project of Poly Changziyang Channel, introduced that the single-width catwalk load-bearing cable uses 16 high-strength steel wire ropes with a diameter of 60 mm and a strength of 2160 MPa to form a stable and reliable load-bearing system; in order to cope with ultra-high With a maximum force of 310 tons, the embedded parts of the load-bearing cables have completed a special anchoring force load test; the entire catwalk system has passed professional wind tunnel tests and can adapt to the complex and changeable sea wind fields in the Pearl River Estuary, laying a solid foundation for structural safety from the source.
"The project uses a rope-climbing robot for the first time in the industry to carry out rope measurement operations, which can reduce the risk of manual high-altitude measurement. The operator can drive the robot through the remote control to collect coordinate data and the precise elevation of the load-bearing cables, and use this to perform rope adjustment work, which can reduce the risk of manual measurement, achieve accurate and intelligent high-altitude measurement operations, and ensure that the 16 load-bearing cables are evenly stressed." Kuang Yicheng introduced.
The project simultaneously built a three-in-one full-dimensional intelligent monitoring system of "structural stress monitoring + equipment condition monitoring + meteorological advance warning". High-precision pressure ring sensors are deployed at key anchoring points to collect anchoring force data 24 hours a day; the east-west anchorage and main tower winch intelligent systems are linked to control the traction force and operating speed in real time; a professional meteorological platform is customized to accurately capture wind speed and rainfall changes in the bidding section, provide early warning of extreme weather, and promote the transformation of catwalk construction from traditional experience models to digital, refined, and scientific management and control, and install a "smart eye" for construction at an altitude of more than 300 meters.
At present, the project team will simultaneously carry out catwalk construction such as surface net laying, guardrail rope installation, and transverse channel erection. It is planned to complete the catwalk erection before the end of this year to ensure that the key processes of main cable erection are carried out efficiently and to promote the construction of this world-class super project with high quality. (over)
