Cantilever Form Traveller

Introduction to Cantilever Form Traveller

Definition and Purpose

A cantilever form traveller is a specialized construction equipment. It is designed to support and position the formwork during the construction of bridges, viaducts, and other structures with cantilevered sections. The main purpose is to create the concrete structure's shape accurately and efficiently. For example, in the construction of a long - span bridge, the cantilever form traveller allows the construction crew to pour concrete for the bridge deck in a step - by - step manner, starting from the piers and extending outwards.

Components and Structure

Main Girder: The main girder is a crucial part of the cantilever form traveller. It usually consists of steel beams that provide the overall structural support. These girders need to have sufficient strength and rigidity to bear the weight of the formwork, fresh concrete, and the construction loads. For instance, in a heavy - duty cantilever form traveller used for a large - scale bridge project, the main girder may be made of high - strength alloy steel with a box - shaped cross - section to enhance its load - bearing capacity.

Formwork System: The formwork attached to the cantilever form traveller is designed to give the desired shape to the concrete structure. It can be made of plywood, steel plates, or a combination of both. The formwork system also includes components such as ties and braces to hold the formwork in place during the concrete pouring process. In a typical application, the formwork is carefully adjusted and aligned to ensure the smoothness and dimensional accuracy of the concrete surface.

Travelling Mechanism: The travelling mechanism enables the cantilever form traveller to move along the construction axis. It usually consists of wheels, rails, and a drive system. The wheels run on the rails, which are installed along the length of the structure being constructed. The drive system can be hydraulic or electric, providing the necessary power to move the form traveller forward or backward. This allows for the continuous construction of the cantilevered section in a controlled and precise manner.

Working Principle

During the construction process, the cantilever form traveller is first positioned at the starting point, usually near a pier or an existing support. The formwork is then set up and adjusted to the correct position and shape. After that, the concrete is poured into the formwork. Once the concrete has set to a certain strength, the form traveller is moved forward to the next construction position using the travelling mechanism. The process is repeated until the entire cantilevered section of the structure is completed. For example, in the construction of a cantilevered balcony of a high - rise building, the form traveller moves along the edge of the building floor by floor, creating the balcony structure with each movement.

Advantages

Enhanced Construction Efficiency: The use of a cantilever form traveller significantly speeds up the construction process of cantilevered structures. It allows for a continuous and systematic construction approach, reducing the overall construction time. Compared to traditional construction methods that rely on scaffolding and piece - by - piece formwork installation, the form traveller can cover a larger construction area in a shorter period.

Improved Quality Control: The formwork attached to the cantilever form traveller provides a consistent and accurate shape for the concrete structure. This helps in ensuring the dimensional accuracy and surface quality of the finished product. The controlled movement of the form traveller also enables better quality control during the construction process, as it reduces the variability caused by manual formwork adjustments.

Increased Safety: By using a cantilever form traveller, the need for extensive scaffolding and other temporary support structures is reduced. This decreases the risk of accidents related to scaffold collapse and improves the safety of construction workers. The form traveller itself is designed with safety features such as guardrails and safety harness attachment points to further protect the workers during the construction process.