Pedestrian bridge over the N231 in Aalsmeer, NL

A fascinating new wooden bridge in the province of Noord-Holland improves the pedestrian connection to the Royal FloraHolland and fits perfectly into the ‘Accessibility Royal FloraHolland’ roof project. In cooperation with the Rotterdam partner wUrck architectuur stedenbouw landschap BV, the Miebach engineering office realised this innovative structure.

The bridge is located to the north-east of the existing transport bridge, with the two structures only half a metre apart and running parallel. The height of the pedestrian bridge is precisely aligned with that of the transport bridge, so that passers-by can take an occasional look at the transport bridge through the windows and witness the impressive hustle and bustle of the auction.

With a total length of 140 metres, the bridge extends as a continuous timber block girder with a constant cross-section, supported by stabilising columns. These supports, which are founded on piles, provide the necessary stability and equalise the ground conditions.

To simulate a continuous structure, the bridge girder is divided into segments whose separation points are strategically located near the moment zero points. The structure is designed so that the timber girder can expand or contract with temperature fluctuations. To compensate for possible deformations, the stairs and lifts are stabilised by separate steel struts. Laying blocks between the bridge girder and supports provide additional flexibility and an even distribution of the bearing stresses.

Prefabricated concrete carriageway slabs are attached to the timber girder and are not firmly connected to the girder. These panels protect the timber girder from rain and also serve as damping. In addition, the underside of the timber girder is bevelled to ensure effective rain protection. The platforms between the lifts and the bridge are cantilevered, which avoids disruptive supports and allows an unobstructed view.