English：

The No. 3 main pier platform of Chizhou Yangtze River Highway-railway Bridge is close to themain channel. There is deep water with high current velocity and geology prone to erosion here. The mainpier cap is embedded,and the foundation is a group of ultra-long bored piles with large diameter. It needshuge and overweight equipment for drilling operation. The main pier drilling platform needs to be erectedduring the flood season. Its design and construction are extremely difficult. After scheme comparison,Thisengineering uses steel casing as the platform foundation for the drilling area, and uses straight piles,inclined piles and anchor piles as the platform foundation for non drilling areas. According to the scheduleand changes in hydrological conditions,this paper calculates and analyzes the construction stages of theplatform during the flood season. It provides theoretical basis for on-site construction, and ensures thesecurity of the platform and the drilling operation proceeded smoothly.