The cantilever casting method has become a highly effective construction method and is mainly applied in constructing medium and large-span bridges. As the key equipment for the cantilever casting method, the hanging basketforming traveler plays an increasingly important role in bridge construction and is highly valued by construction units. This article will delve into the mechanical principles and characteristics of the form traveler and focus on the design and construction processes of the front support form traveler and the rear support form traveler.

Structure and Construction of the Front Support Form Traveler

1.1 Structure of the Front Support Form Traveler

The main components of the front support form traveler include: the formwork system, the load-bearing system, the anchoring system, the cable-hanging system, the walking system and the thrust restraint system.

Formwork system: Its components include the inner formwork, the bottom formwork, the outer side formwork and the diaphragm. Forms of plate-ribbed beams and box-shaped beams can be designed according to different main beam structures.

1.2 Construction of the Front Support Form Traveler

Firstly, carry out the construction of the 0# block concrete. Its position is right above the bridge pier. Pouring it is to form a site for the installation of the hanging basket. When pouring the pier table, brackets or supports should be set on both sides of the bridge pier. Secondly, conduct the operation of assembling the form traveler. After the form traveler is transported to the construction site, it should be trial-assembled on the trial assembly platform so as to detect in time problems such as deformation caused during the transportation process and poor manufacturing, and then ensure the smooth progress of the formal installation. Thirdly, carry out the test work before the formal installation. After the assembly of the form traveler is completed, a load test should be conducted to check whether the actual internal force of the form traveler structure and the deformation meet the design requirements, and fully understand the elastic and inelastic deformation of the form traveler, and then determine the elevation of the formwork during the construction process. Finally, carry out the construction with the form traveler.

2. Structure and Construction of the Rear Support Hanging Basket

2.1 Structure of the Rear Support Form Traveler

Platform system: During the construction process, the main function of the platform system is to provide a platform to realize operations such as pouring concrete, adjusting the elevation of the formwork and setting up the formwork. Its main components include the front and rear supporting beams, the bottom formwork longitudinal beams, the lifting beams inside the roof box chamber and under the flange plates.

Anchoring system: Use 32-mm-diameter precision-rolled threaded steel to connect the main truss and the construction platform for anchoring, and fasten the nuts and bolts. Anchor the front hanging point on the front carrying beam, and anchor the rear hanging point on the rear carrying beam and the bottom plate of the already-poured concrete main beam. Anchor the rear anchor beam on the concrete main beam through the precision-rolled threaded steel and transfer the overturning moment to the main beam through the precision-rolled threaded steel.

Formwork system: Its components include the inner formwork, the bottom formwork and the side formwork. The side formwork is suspended on the external hanging beam and the external guide beam. It adopts a steel section framework with round rollers set on the framework to help the formwork move forward. The bottom formwork is placed on the bottom formwork longitudinal beam and adopts a truss-type steel framework.

2.2 Construction of the Rear Support Form Traveler

Firstly, carry out the construction of the A0# block. During the construction process, mainly use the bracket corbel. During the construction of the pier body, pre-embedded parts should be set first, and the load of the corbel bracket can be transferred to the pier body. Secondly, conduct the assembly of the form traveler. To ensure the smooth progress of the installation, after the hanging basket is transported to the construction site, it should be trial-assembled on the shore to detect problems in time. Thirdly, move the hanging basket, which mainly includes three aspects: the formwork movement, the movement of the main truss and the side formwork slideway, and the positioning of the side and bottom formwork. Finally, conduct the preloading operation of the form traveler.

Conclusion

During the bridge construction process, the form traveler is a very important tool. It is convenient to use and can effectively improve the construction efficiency in the construction. The design and construction of the hanging basket have a very large development space in the future, and it is worthy of continuous research by relevant workers.