e-mosty December 2017 MSS and Formwork Travellers | Page 45

Figure 2 + 3: Location of the bridge on the map To avoid disrupting canal traffic, the works have to be carried out outside the shipping channel, which means the deck has to be cast in place. The contract also includes construction of access viaducts on either side of the bridge with a total length of 2 km, together with connections to the existing road network. Both the form travellers and the lifting structures were designed and fabricated specifically for the project. The form travellers are a system of formwork panels and steel structures that allow casting of an external constant cross section segment of 8m length in order to construct the bridge deck. This system can be adapted, by removing some panels, to make 7m long segments as required by the client. The inner formwork can also adapt to the different interior cross sections of the segment configurations. The form travellers are provided with working platforms with steel grated flooring, ladders and guardrails allowing access to different parts of the formwork. Figure 4: Rendering of the bridge Source: vinci-construction.com/en/project/15892/atlantic-bridge-panama RĂºbrica Engineering, which is a Spanish company with more than 20 years of experience in the design and manufacturing of special equipment for civil construction, has designed and supplied four form travellers (two for each bridge pylon) for the segmental construction of the bridge deck. Additionally, four lifting structures for the lifting of the travellers were also designed and provided. 4/2017 The structure consists of a steel casting cell supported by a grillage of transversal and four longitudinal steel girders. These girders are located under the deck. During casting of each typical segment, each one of the longitudinal girders is supported by four bars anchored to the previous concrete segment working as a cantilever. During launching, the whole system lies over a pair of rails which incorporate hydraulic cylinders; so that the system weight is carried by the upper part as it moves forward. The system also includes 2 back support points at the bottom of the previous concrete segment, fitted with rollers.