Continuous strand jack system for Hefei-Fuzhou railway Tongling Yangtze bridge construction

Project name:

Intelligent continuous strand jack synchronous system applied in Hefei-Fuzhou railway Tongling Yangtze bridge 
 

Project profile: 
The length of Tongling Yangtze Bridge is about 6000m, It’s a new key project of Hefei- Fuzhou passenger railway. It was composed of north approach bridge, river-crossing main bridge and south approach bridge. The main bridge is a highway-railway bridge, under-layer designed quadruple track railway, upper layer designed six-lane highway. Tongling Yangtze bridge is a two tower five span steel truss girder bridge, the full length of girder is 1290m, steel truss main girder use N glyph truss, totally 86 internodes and 45 hoisting segments, the max weight of single piece is 366 tons, north shore steel girder side-span use KATTOR CSS to build, main tower steel girder use double cantilever to build.

Project challenges:

The construction project was built in the narrow part of Yangtze river, and the construction period is in flood season, how to solve the working condition of deep foundation, river-way narrow, rapid flow and so on complex terrain.
The length of main span is about 630 meters, create a world most of same type highway-railway dual-purpose cable-stayed bridge, should adopt what kind of technical solution to shorten the construction period, finish steel girder erection.
Synchronous lifting equipment how to ensure the safety of steel truss girder structure during the process of girder Lifting and lowering.

Solution:     
After lots of technical exchange between KATTOR R&D team and construction builder, based on incremental launching method and the terrain differences of both shore, KATTOR designed different solution for north and south shore construction: south shore side-span adopted all launching; north shore side-span adopt partial launching for the part on shore. 
South shore adopted three kinds of cylinders with 650 tons, 800 tons, 1000 tons which have hydraulic self-locking function, intelligently remote control multi cylinder synchronous lifting and lowering by PLC, implement lifting, lowering, remain with load safely.

This project adopted KATTOR CSS to ensure all cylinders’ synchronized operation. Set up a jacking platform on the shore side and multi temporary bridge pier to opposite shore along bridge direction. Install a set of CSS cylinders on left and right side of each temporary bridge pier. Each cylinder equipped with an independent hydraulic pump station, has independent controller to implement front control, and communication with the main controller through field bus. Computer system control CSS and SLS(synchronous lifting system), to adjust height of each pier, control pulling force and speed according to the supporting force, ensure the pulling force match friction of each pier, at the same time adjust the position of steel box girder.