Project Case: Walking Type Synchronous Pushing Hydraulic System for Steel Box Girder Bridge Launching

Project Overview

In this project, a Walking Type Synchronous Pushing Hydraulic System was successfully applied to the incremental launching of a steel box girder bridge.

The project involved precise positioning of large-span steel box girders under strict alignment and deformation control requirements, while construction activities had to be carried out above existing traffic corridors with limited working windows.

The walking-type synchronized pushing solution provided a safe, controllable, and repeatable construction method, meeting both structural and site constraints.

1. Engineering Background and Challenges

The bridge superstructure consisted of large steel box girder segments, assembled behind the abutment and launched longitudinally to their final position.

Key engineering challenges included:

• Low bending stiffness of steel box girders during launching
• High sensitivity to uneven vertical support forces
• Strict displacement and alignment tolerance requirements
• Construction above active roads and urban infrastructure
• Limited nighttime or off-peak working windows

Traditional methods such as continuous pulling systems or large crane erection posed unacceptable risks and operational constraints.

2. Selected Construction Method

After evaluating multiple construction options, the EPC team selected a Walking Type Synchronous Pushing Hydraulic System, specifically designed for incremental bridge launching applications.

System Configuration:

• Modular walking-type pushing units installed at multiple pier tops
• Ultra-high pressure hydraulic cylinders for compact and high-capacity operation
• Centralized frequency conversion synchronous control system
• Double closed-loop control integrating:Displacement feedback, Hydraulic pressure (force) feedback

This configuration ensured stable load sharing and synchronized movement throughout the entire launching process.

3. Launching Procedure Description

The bridge launching operation was executed through repeated, controlled walking cycles.

Step-by-Step Launching Process

① Vertical support and load balancing

Each walking unit provided adjustable vertical support, automatically balancing load differences caused by structural flexibility or pier elevation variation.

② Synchronized longitudinal pushing

Horizontal pushing cylinders advanced the steel box girder incrementally. All pushing points operated under synchronized speed and displacement control.

③ Real-time monitoring and correction

Displacement sensors and pressure transducers continuously monitored system behavior. Any deviation was corrected automatically in real time.

④ Continuous walking cycles

The lifting–pushing–lowering–reset cycle was repeated until the bridge reached its final design position.

Throughout the operation, no abnormal deformation or excessive differential displacement was observed.

4. Project Results and Engineering Performance

The walking type synchronous pushing system delivered the following results:

• Stable and smooth launching of large steel box girders
• Uniform vertical force distribution at all pier tops
• Millimeter-level displacement control accuracy
• Minimal impact on traffic and surrounding structures
• High construction safety with predictable system behavior

The synchronized control system effectively compensated for friction variation, structural stiffness differences, and site tolerances.

5. Application Value for EPC Bridge Projects

This project demonstrates that Walking Type Synchronous Pushing Hydraulic Systems are particularly suitable for:

• Steel box girder bridges
• Composite and truss bridge structures
• Bridges crossing active highways or railways
• Bridge replacement and fast-track installation projects

For EPC contractors, this method provides a proven, repeatable, and controllable construction solution for complex bridge launching scenarios.

6. System Capabilities and Equipment Highlights

The system used in this project offers:

Load capacity options up to 1000 tons per unit

Customizable vertical and horizontal stroke lengths

Synchronized displacement and force control

Modular design for fast installation and removal

Compact footprint suitable for congested construction sites

System configuration can be tailored according to bridge span, girder weight, pier spacing, and construction sequence.

Conclusion

This project confirms the effectiveness of Walking Type Synchronous Pushing Hydraulic Systems in steel box girder bridge launching applications.

By combining walking-type mechanical design with advanced synchronized hydraulic control, the system enables safe, precise, and efficient incremental launching under demanding engineering conditions.

For EPC contractors facing complex bridge erection challenges, this technology represents a reliable and field-proven solution.

Planning a bridge launching or replacement project?

Our engineering team supports EPC contractors with:

• Construction method evaluation
• System configuration selection
• Preliminary load and synchronization analysis

Contact us with your project parameters (span, girder type, weight, pier layout) to discuss a suitable walking type synchronous pushing solution.