World's Largest-Span Self-Anchored Suspension Bridge Enters Main Construction Phase

Rendering of the Wanlong Bridge

On October 23, the first pile foundation of the Wanlong Bridge in Nansha, Guangzhou—currently the world's largest-span self-anchored suspension bridge, designed by China Railway Siyuan Survey and Design Group and constructed by China Railway Construction Bridge Engineering Bureau Group—was officially drilled, marking the entry of another world-class bridge in the Guangdong-Hong Kong-Macao Greater Bay Area into the main construction phase.

The Wanlong Bridge is located in Nansha District, Guangzhou. As an urban arterial road, it crosses the Longxue South Waterway and serves as an important river crossing linking the Wanqingsha town area with the Longxue Island International Shipping and Logistics Center. The bridge has a total length of 1,150 meters and a main span of 608 meters, making it the world's largest-span self-anchored suspension bridge and the world's first spatial-cable self-anchored suspension bridge to adopt elliptical steel bridge towers. The pile foundation under construction is Pile No. 5 of the Z4 main pier, with a designed length of 96 meters, the longest pile of the main pier.

The main pier pile foundation of the Wanlong Bridge uses 29 piles with a diameter of 3 meters, which are large-diameter ultra-deep bored piles involving considerable construction difficulty. The drilling operation must pass through unfavorable strata such as silt (about 30 meters thick), silty clay, sand layers, broken layers, boulders, and weathered rock, and in particular must cross a fault zone whose fracture plane lies 50 meters below the riverbed. While preventing borehole collapse, the verticality of the ultra-long piles must also be ensured.

To overcome the risk of borehole collapse during drilling that may be caused by adverse geological conditions, the builders adopted measures such as installing long steel casings, mixing high-performance slurry, and promptly replenishing freshly prepared slurry during drilling to maintain stable performance. At the same time, through precise control of drilling pressure and detection with an ultrasonic borehole inspection instrument, the quality of the completed piles was ensured. During drilling and hole cleaning, the builders used a mud-sand separator to load the separated sand and gravel into slag boxes, which were cleaned, loaded onto trucks, and transported to disposal sites on schedule. No pollutants were discharged into the water throughout the process, effectively protecting the water environment.

With the theme of "Bright Moon over Nansha," the Wanlong Bridge incorporates bridge aesthetics into its design, drawing on the "cultural symbol" unique to local Lingnan architecture—the wok-ear house—to deliver a striking example of modern bridge aesthetics.

Once completed, the Wanlong Bridge will help build a comprehensive multimodal three-dimensional transport network integrating ports, railways, highways, and municipal roads, continuously enhance the outward radiation capacity of the Longxue Island International Shipping and Logistics Center in Nansha, turn Nansha District into a strategic fulcrum of the Pearl River Delta for the Maritime Silk Road and the Silk Road Economic Belt, and support the high-quality and rapid development of the Guangdong-Hong Kong-Macao Greater Bay Area.