The Xingyi Yangtze River Bridge has a total length of 2,343 meters and a main span of 1,120 meters, making it the longest-span double-deck suspension bridge on the upper reaches of the Yangtze River. The pile foundation construction for the main pier on the north bank of the bridge can be described as "surgery on a cliff": the construction area is located below a Class 7 high and steep slope on the north bank of the Yangtze River, and the working conditions are extremely harsh. The main pier pile foundation is designed with a diameter of 3.0 meters and a pile length of 70 meters; the concrete volume of a single pile exceeds 520 cubic meters, and the reinforcement cage weighs 56 tons. The project faces multiple challenges, including great hole depth, large pile diameter, high concrete volume for a single pour, heavy reinforcement cages, and an extremely narrow construction site.

Faced with these numerous difficulties, the project team adhered to scientific coordination and precise measures. Lightweight concrete filling was used to complete the construction platform, laying a solid "workbench" for construction operations; the operation plan of "excavate and transport immediately, dry and wet zones separated" was implemented to efficiently solve the problems of earthwork disposal and environmental protection. At the same time, rotary drilling rigs were used for layered drilling to strictly control hole-forming quality; a 150-ton crawler crane, together with special lifting equipment, was used to hoist the 56-ton reinforcement cage in sections and steadily "implant" it into place; the tremie method was adopted for continuous pouring, with strict control of the concrete mix ratio, slump, and tremie pipe embedment depth to ensure pile quality. A series of measures effectively ensured the safe, high-quality, and efficient progress of pile foundation construction under complex conditions.

Next, the project will continue to maintain its攻坚 posture and advance at full speed the batch construction of the main pier pile foundations, strictly controlling safety, quality, and schedule to ensure the efficient achievement of node targets and to accelerate and improve the efficiency of project construction.

Source: Sichuan Road & Bridge