Main Pier Cofferdam of Huaihe River Grand Bridge Successfully Sealed at Bottom

On August 5, after 41 hours of continuous pouring, the main pier cofferdam of the Huaihe River Grand Bridge, constructed by the TJ-03 project of the Mingguang-Bengbu section reconstruction and expansion project of the G36 Ningluo Expressway undertaken by China Railway No.4 Engineering Group, was successfully sealed at the bottom. This marks the official transition of this key control project on the important highway connecting the Yangtze River Delta economic circle from "underwater" to "above water" construction.

The Mingguang-Bengbu section reconstruction and expansion project of the Ningluo Expressway starts at the Mingguang East Interchange in Mingguang City and ends at Meiqiao Town in Bengbu City, with a total route length of 80.903 kilometers. China Railway No.4 Engineering Group undertakes Section 03, which is located in Fengyang County and Wuhe County of Anhui Province, with a route length of 9 kilometers. The bridge tower height reaches 148.6 m, with high precision requirements, making it a key control project for the entire line.

The double-wall steel cofferdam of the main pier of the G36 Ningluo Expressway Huaihe River Grand Bridge has a total height of 38 m, equivalent to a 12-story building, making it the deepest-embedded main pier cofferdam of a cable-stayed bridge in the Huaihe River to date. During the flood season, the maximum water depth can reach 13-17 m. The cofferdam of Pier 22 is embedded 19.65 m into the riverbed. The geology at the main pier is relatively complex and close to the existing expressway bridge piers. During the lowering process, it needs to penetrate residual stones, fine sand, round gravel soil, completely weathered mudstone and other soil layers from the old bridge construction, with high friction resistance. The hard completely weathered mudstone has strong cohesion, making conventional suction dredging excavation difficult. To ensure the one-time success of this steel cofferdam bottom sealing, the owner unit provided on-site guidance, the supervision unit conducted on-site monitoring, and the project department planned ahead and arranged scientifically, organizing experts in advance to review the bottom sealing construction plan, refining the division of labor for each construction team, and repeatedly conducting briefings. During the bottom sealing process, technical personnel monitored and measured in real time, strictly controlling the bottom sealing elevation and quality, and ultimately successfully completed the bottom sealing task of this steel cofferdam.

The Mingguang-Bengbu section of the G36 Ningluo Expressway is an important component of the G36 Ningluo National Expressway, a strategic major corridor from the Yangtze River Delta region to Anhui, Henan, Shaanxi and the Northwest regions, and an important highway connecting the Yangtze River Delta economic circle. The construction of this project is of great significance for promoting the rise of central Anhui, driving the revitalization of northern Anhui, promoting economic development in northern Anhui, and accelerating the integrated construction of the Yangtze River Delta.