Korea KTX Bridge underpinning Project
Project Overview :
An underground tunnel is planned to pass beneath a section of the Korea KTX High-Speed Railway Bridge. To facilitate this, the existing pile elements supporting Piers 28 and 29 must be relocated. A new foundation has been constructed, and the load from the old piles must be transferred to the new foundation to allow for their removal and subsequent tunnel construction.
The tunnel construction will span several years, during which the KTX railway must remain fully operational without interruptions. Given the high travel speed of the trains, the rail level must be maintained within a strict tolerance of ±5 mm throughout the entire construction period to ensure safety and stability.
Our solution
To achieve seamless load transfer and maintain the required level tolerance, YIPU Hydraulic’s engineering team designed and supplied a computer-controlled underpinning system.
A total of 91 lock nut jacks, each with a 200-ton capacity, were installed between the pile cap and the beams connected to the new pile cap.
During the preloading phase, calculated loading data for each jack is input into the controller, which precisely manages the load distribution to transfer the entire pier load onto the new piles via the cross beam.
Once the load is fully transferred, the old piles are cut and removed. The controller continuously monitors both the load on each jack and the displacement between the beam and the pile cap during the pile-cutting process to ensure precise pier leveling.
Load and height data are logged and stored in the controller for retrieval as needed. Additionally, a line level sensor system operates 24/7 to monitor pier level changes throughout the construction period, ensuring the safe operation of the high-speed railway.
System consisted
1. 91 lock nut jacks with 200-ton capacity
2. 4 hydraulic power packs
3. 2 computerized controllers
4. 1 line level monitoring system
