July 26

As the last batch of concrete was poured into the tremie pipe

XCMG rotary drilling rigs were involved in the construction of the

Chizhou Yangtze River Highway-Railway Bridge

lasting 100 days 

the construction of 77 bored piles for the main pier on the south bank was completed ahead of schedule

The Chizhou Yangtze River Highway-Railway Bridge has a total length of 3.1 kilometers, with a main bridge length of 1,768 meters. It is a three-main-truss, three-cable-plane double-deck steel truss cable-stayed bridge with a main span of 812 meters, featuring long span, heavy load and high speed.

The foundation of Pier No. 4 completed in this construction adopted a total of 77 bored cast-in-place piles, with a maximum pile length of 138.5 meters and a maximum bore diameter of 2.8 meters, and an average rock penetration depth of about 110 meters, imposing high requirements on the performance of the hole-forming equipment.

The lithology at the main pier No. 4 mainly consists of silty mudstone, mudstone and siltstone, and the rock strata are prone to softening and disintegration when exposed to water. As the main pier of the bridge is a pier in the river, the underwater construction environment of the Yangtze River where the main pier is located is complex, with turbulent currents and large elevation differences on the riverbed surface, and the soil layers to be drilled are relatively hard, which brings certain difficulties to the construction of the ultra-long and ultra-deep pile foundations of the bridge. In addition, the working area on the river platform is narrow, making safety the top priority of the work.

To ensure the verticality of the drill bit penetrating into the rock and the precise centering of the hole position, the project department deployed a total of 8 large rotary drilling rigs of graduated sizes, including XR800HD, XR700E, XR600E and XR580HD, and adopted a two-stage hole-forming and stage-by-stage reaming process to overcome drilling difficulties, ensure drilling safety and improve drilling efficiency while also meeting the requirements for borehole verticality.

It is understood that the Chizhou Yangtze River Highway-Railway Bridge is a comprehensive cross-river transportation project integrating a high-speed railway and an expressway. It spans the north and south banks of the Yangtze River, connecting Tongling City and Chizhou City in Anhui Province, with the expressway on the upper deck and the railway on the lower deck. To match the long span and the high load requirements of multiple highway and railway lines, the bridge specially adopts the design of a three-main-truss, three-cable-plane double-deck steel truss cable-stayed bridge to improve the bearing capacity of the bridge. After the bridge is completed and put into operation, it will be the 6th highway-railway bridge crossing the Yangtze River in Anhui Province.