Bridge construction is a complex and critical process that demands precision and efficiency. Among the various construction methods for launching gantry cranes, full-span assembly and segmental assembly are two commonly used methods, each catering to specific bridge structures. In this article, we will mainly introduce these two construction methods for launching gantry, focusing on their definitions, characteristics, and applications.
Full-span Assembly Method for Launching Gantry Cranes
The full-span assembly is a bridge construction method where the entire bridge span is prefabricated in a factory and then transported to the construction site for installation.
Characteristics of the Full-span Assembly Method
The primary characteristic of the full-span assembly for launching gantry crane is the prefabrication of the entire bridge span in a controlled factory environment. This method ensures high construction quality and efficiency, minimizing on-site construction period.
The bridge components, including beams, decks, and other structural elements, are manufactured with precision in the factory. This approach allows for rigorous quality control, reducing the likelihood of errors during the assembly process.
The efficiency of whole-span assembly significantly shortens the construction period, making it an attractive option for projects with tight timelines.
Segmental Assembly Method For Launching Gantry Cranes
Segmental assembly method for launching gantry crane involves dividing the entire bridge span into segments along a direction perpendicular to the longitudinal axis of the bridge. These segments are prefabricated in a factory and assembled on-site using specialized equipment, often prestressed at the same time, so that it becomes an overall structure, and then progress segment by segment in the predetermined installation direction, or symmetrically balanced cantilever assembly.
Applications of Segmental Assembly Method
Segmental assembly is divided into two major techniques: the span-by-span assembly method and the T-symmetrical assembly method.
The former is mainly employed for simply supported bridge structures, while the latter is commonly used for continuous girder or continuous rigid frame structures.
Characteristics of Segmental Assembly Method
Segmental assembly provides advantages such as lightweight segments for easy transportation, minimal impact on traffic and the environment during bridge construction, and a significant reduction in the effects of concrete shrinkage and creep after bridge completion.
Choosing the Right Construction Method For Bridge Girder Launching Gantry Crane
The selection between full-span assembly and segmental assembly depends on various factors, including bridge design requirements, geographical conditions, and specific construction circumstances.
Bridge Design Requirements:
For projects where a continuous and high-quality bridge structure is crucial, whole-span assembly is often preferred. This method ensures uniformity and precision in the prefabricated components, meeting stringent design specifications.
Segmental assembly, on the other hand, is versatile and can be adapted to different bridge designs, making it suitable for a wide range of projects.
Geographical Conditions:
The geographical features of the construction site play a significant role in method selection. Whole-span assembly may be preferred in locations where transportation of large prefabricated components is feasible.
In areas with challenging terrain or restricted access, segmental assembly’s modular approach allows for easier transportation of smaller segments, reducing logistical challenges.
Construction Circumstances:
Project timelines, budget constraints, and on-site conditions influence the choice between these methods. Whole-span assembly is advantageous for projects with strict timelines, as it reduces on-site construction duration.
Segmental assembly is suitable for projects where on-site conditions or restrictions necessitate minimal disruption to traffic or the environment during construction.
In bridge construction, the choice between full-span assembly and segmental assembly for launching gantry crane is not a one-size-fits-all decision. Both methods offer unique advantages, and their suitability depends on the specific requirements of the project. To learn more about our launching gantry cranes, contact Aicrane today.