The cantilever form traveller construction method refers to the construction method of balanced and pouring or assembling girder sections section by section towards the middle of the bridge span on a working platform set on both sides of the bridge piers, until the bridge span structure is connected. The form traveller cantilever construction method is currently one of the most widely used methods for large-span pre-stressed concrete cantilever beams, continuous beams, and rigid frame bridges in the industry. This article will introduce the form traveller cantilever form traveller construction method.
Advantages of Form Traveller construction
The advantages of form traveller cantilever construction method mainly include the following three aspects:
1) It does not require large support structures or temporary equipment;
2) During the construction period, it does not affect the traffic flow under or over the bridge;
3) It fully utilizes the strong ability of prestressed concrete structures to withstand negative bending moments, transferring the positive bending moment at the mid-span to negative bending moments at the supports, thus improving the bridge's ability to span.
Cantilever Construction Steps
The general steps of the cantilever construction method are as follows: firstly, pour block 0 at the top of the pier; secondly, cast the cantilevered segments with forming traveller; and then, construct the combined segments and convert the structural system.
When cast-in-suspension girder body is divided into segments, the length of block 0 is generally 5~10 m, and the other beams are generally 2.5-5 m. The construction period of a beam section usually takes 6-10 days.
The construction period for a beam section usually takes 6-10 days. Based on prior design and construction experience, the number of beam segments should be increased without affecting the construction period, so that the results of reinforcement calculation are more accurate and the overall structure is more evenly stressed. Additionally, the closure section is mostly 2-3 meters in length.
