On the morning of March 8th, with the roaring startup of a 550-ton rotary drilling rig, the drilling of the main pier foundation for the Hailong Bridge, a key control project of the Guangzhou-Zhuhai section expansion, commenced smoothly. This marked another major progress for the project following the successful completion of the first traffic diversion from Zhongshan urban area to Zhuhai Toll Station.
The Guangzhou-Zhuhai section expansion project starts from the Tanwei Interchange in Huangge Town, Nansha District, Guangzhou, passes through Huangge Town, Hengxi Town of Nansha District, Guangzhou, Sanjiao Town, Minzhong Subdistrict, Gangkou Town, Torch Development Zone, and Nanlang Subdistrict of Zhongshan City, and ends at the Zhuhai Toll Station in Nanlang Subdistrict, Cuiheng New District, Zhongshan City, with a total length of approximately 50.4 km. The key control project, the Hailong Bridge, spans across the Xiaoluan Waterway and Jiyawaterway. The Xiaoluan Waterway Bridge adopts a twin-tower twin-cable prestressed concrete cable-stayed bridge with a span combination of (135+255+135) m and a total length of 525 m for the main bridge. The Jiya Waterway Bridge adopts a prestressed concrete continuous rigid-frame bridge with a span combination of (120+170+99) m and a total length of 389 m for the main bridge. As the old bridge is located on a large-radius horizontal curve, to accommodate the road alignment requirements and minimize land acquisition, the new bridge will be designed as a large-span curved cable-stayed bridge.
The main pier foundation of the Hailong Bridge consists of 42 piles (26 for the Xiaoluan Waterway Bridge and 16 for the Jiya Waterway Bridge). This drilling is for pile Z3-3 of the Xiaoluan Waterway Bridge, with a length of approximately 68 m and a designed concrete volume of 483 m³ per pile. The main pier foundation will adopt 3m diameter bored cast-in-place piles. Due to the complex geological conditions in the construction area, with soft soil layers such as silty clay over 30m thick, and the proximity of the new bridge piles to the old bridge and river embankment, this construction adopts measures such as using 36m long steel casing and optimizing the CMC (clay/mineral/chemical) slurry mix ratio to prevent disturbance to the old bridge and river embankment.
“Pile drilling is one of the most important steps in the construction of bored cast-in-place piles. To ensure the quality of the borehole, detailed geological surveys of each stratum are conducted before drilling, and key processes such as drill rod pressure, drilling rate, slurry parameters, and underwater concrete pouring are strictly controlled. Additionally, an on-site solidification technique is employed to treat the discarded slurry, achieving green recycling of the slurry and ensuring the pile quality while protecting water resources,” explained the project manager.
The project commenced construction in November 2022 and is scheduled for full completion and opening to traffic in 2027. The section from Zhongshan urban area to Zhuhai Toll Station, approximately 15 km long, is expected to be completed and open to traffic by June 2024. As an important component of the “A-shaped” core development axis in the core area of the Guangdong-Hong Kong-Macao Greater Bay Area, the project bears the task of being the transportation corridor along the west bank of the Pearl River in the Greater Bay Area. Upon expansion, it will further enhance the connectivity and traffic capacity of the cross-river passages at the Pearl River Estuary.