Adjustment devices—such as submerged hydraulic jacks—are installed on all sides of the steel column at the tremie-concrete section of the bored pile. By extending or retracting these devices, the verticality of the steel column can be precisely adjusted.
This method allows the adjustment devices to be positioned close to the concrete placement level near the column base, enabling effective correction with relatively small reaction forces. Although the procedure involves more detailed steps, it provides significantly improved vertical alignment accuracy during steel column installation.
TungFeng has developed a patented Steel Column Installation Method for Top-down Construction, which significantly improves the vertical alignment accuracy of installed steel columns. This method reduces the need for on-site corrective works such as reinforcement, coupler adjustments, and the welding of connection plates that typically arise from column misalignment.

- Provides sufficient time for precise positioning and adjustment of steel columns
- Column alignment is minimally affected by buoyancy, especially for large but lightweight sections
- No special concrete admixtures required, ensuring consistent construction quality
- Underwater jacks allow full-length adjustment of columns before concrete initial set, not just at the top