Zhuojin Pipe Fitting Co., LtdResearch on Hoisting Construction Technology for Steel Tubular Concrete Arch Bridge Ribs
Literature Overview
The study by Wang Wei, Yuan Ye, and Zhou Jie from Zhejiang Provincial Construction Investment Transportation Infrastructure Group Co., Ltd., published in the Journal of Xuzhou University of Technology (Natural Science Edition) (2025, Vol. 40, No. 2), investigates the hoisting construction technology for the arch ribs of an upper-supported steel tubular concrete arch bridge. Based on the construction of the 170 m Hongkou Bridge, the research employs numerical simulation and cable force comparison analysis to evaluate two hoisting strategies: single-span hoisting and integral hoisting. Funded by the Zhejiang Provincial "Sharp Soldier" and "Leading Goose" R&D Program (2023C03183), this work addresses practical construction challenges in large-span arch bridge engineering.
Project Background
The Hongkou Bridge, with a span of 170 m, is an upper-supported steel tubular concrete arch bridge. The arch rib construction is a critical phase that determines the overall structural integrity and construction safety. The two primary hoisting strategies under consideration are:
- Single-span hoisting: Each half of the arch rib is erected and hoisted separately, with the two halves meeting at the crown.
- Integral hoisting: The complete arch rib is assembled on the ground at high precision and then hoisted as a single unit.
Each strategy has distinct advantages and challenges that must be carefully evaluated for a given project.
Technical Analysis of Hoisting Strategies
Single-Span Hoisting
Single-span hoisting involves erecting each half of the arch rib in segments, with the two halves converging at the crown. This approach offers:
- Advantages: Lower equipment requirements, greater flexibility in scheduling, easier management of wind effects during erection, and reduced risk of catastrophic failure if a problem occurs during hoisting.
- Challenges: Higher risk of working at height during segment connection, more complex alignment and splicing procedures, potential for differential settlement between the two halves, and longer overall construction time.
Integral Hoisting
Integral hoisting requires the complete arch rib to be assembled on the ground with high precision before being lifted into position. This approach offers:
- Advantages: Reduced high-altitude work risk, faster on-site assembly, better control of joint quality, and simpler alignment procedures.
- Challenges: Requires high-precision ground assembly, demands higher bearing capacity from the cable hanging system, requires large lifting equipment, and necessitates comprehensive consideration of environmental factors during the critical hoisting operation.
Cable System Design Requirements
The paper emphasizes that the cable hanging system design must account for multiple complex factors:
| Factor | Description | Design Implication |
|---|---|---|
| Slack effect | Cable elongation under load reduces effective tension | Must provide adequate initial tension |
| Wind-induced vibration | Dynamic loading from wind during hoisting | Must include dynamic amplification factors |
| Uneven loading | Asymmetric load distribution during hoisting | Must design for worst-case asymmetric conditions |
| Impact loading | Sudden load application during connection | Must include dynamic impact factors |
The paper specifies that the strength safety factor for the cable system should be no less than 2.5, which is a stringent requirement reflecting the critical nature of the hoisting operation.
Numerical Simulation Parameters
The numerical simulation incorporated the following environmental and geometric parameters:
- Temperature effects: Thermal expansion and contraction of the steel arch rib during hoisting
- Wind speed effects: Dynamic loading from wind during the critical hoisting phase
- Wire rope angle effects: The geometry of the hoisting cables and their effect on load distribution
These parameters are essential for ensuring construction safety and must be accurately represented in the simulation model.
Engineering Practice Implications
- Strategy selection criteria: The choice between single-span and integral hoisting should be based on a comprehensive evaluation of site conditions, available equipment, environmental factors, and risk tolerance. For the 170 m span of the Hongkou Bridge, the specific site conditions and equipment availability would determine the optimal strategy.
- Ground assembly precision: For integral hoisting, the ground assembly must achieve high dimensional accuracy to ensure proper fit-up upon hoisting. This requires careful surveying, alignment, and temporary bracing during assembly.
- Cable system design: The cable hanging system is the critical component of the hoisting operation. The design must incorporate all identified factors (slack, wind, uneven loading, impact) with appropriate safety margins. The specified safety factor of 2.5 is consistent with best practices for critical lifting operations.
- Environmental monitoring: During the hoisting operation, real-time monitoring of temperature, wind speed, and cable forces is essential to ensure that conditions remain within the design envelope. Weather forecasting should be integrated into the construction schedule to identify optimal hoisting windows.
- Contingency planning: Given the inherent risks of large-span arch rib hoisting, comprehensive contingency plans must be developed, including procedures for weather delays, equipment failure, and emergency response.
Critical Reflections
The paper provides valuable insights into the technical requirements for arch rib hoisting, but several aspects could be further developed. First, the specific numerical simulation results are not detailed in the abstract, making it difficult to assess the quantitative differences between the two hoisting strategies. Second, the paper does not address the economic comparison between single-span and integral hoisting, which is often a decisive factor in strategy selection. Third, the long-term structural performance implications of the hoisting method (residual stresses, initial deflections, joint quality) are not discussed.
The emphasis on the cable system safety factor of 2.5 is appropriate but should be contextualized within the relevant standards (such as GB 50017 for steel structure design and GB 50205 for steel structure construction quality acceptance). The specific cable forces and loads would need to be verified against these standards for a complete engineering assessment.
Study Insights and Recommendations
This research contributes practical knowledge to the construction of steel tubular concrete arch bridges, which are increasingly used for medium and large spans due to their structural efficiency and aesthetic appeal. The key insight is that the hoisting strategy selection is not merely a matter of preference but requires rigorous technical analysis considering multiple interacting factors. For engineers involved in similar projects, the recommendations are: conduct detailed numerical simulations incorporating all relevant environmental parameters, design the cable system with a minimum safety factor of 2.5 accounting for all identified loading scenarios, implement comprehensive real-time monitoring during the hoisting operation, and develop detailed contingency plans. The experience gained from the Hongkou Bridge project should be documented and shared to benefit the broader bridge engineering community.