Rafting Bridge
The new bridge for pedestrians and cyclists across Savinja replaced a former footbridge which was placed low over the river and posed a constant risk of flooding for the city. The location of the new footbridge lies on the axis connecting the Museum square in front of the Central Library on the left bank, with the promenade in the town park on the right bank of the Savinja River. In a wider context the footbridge connects the medieval town center on the left bank with the town park on the right bank. On the right bank the existing footbridge connects to footpaths and bicycle paths running along Partizanska street, on the left bank it intersects Badovinčeva street and connects to the foot path along the Savinja embankment, and across the Museum square into the system of footpaths and bicycle paths throughout the town.
Due to the flood protection measures along the Savinja River, it was necessary to raise the level of the existing footbridge, raise the level of the flood protection dikes along the river, carry out a planning intersection of the footpath and bicycle path connection to the town park and the Partizanska street. Such were the starting points, representing the context for planning the replacement of the Splavarska brv footbridge. The new construction complements the iconography of existing spatial elements. It preserves the grace of the old town panorama and offers a cultural dialogue between the old and the new. Each era leaves a mark in the space with a new bridge. Therefore the
decision on the choice of the bridge construction and thus its architectural and symbolic image was aimed at finding a long span object with the bridge beam as thin as possible. The
bridge was to span the river in one leap. The new footbridge therefore will not compete with the ambiance of the town scenery by being extravagant or garish, but will complement it with a youthful elegance and boldness, which are made possible by using new technologies and knowledge.
BATTLE FOR CENTIMETERS
In designing the construction plans that would correspond to the above mentioned basic premises we encountered three seemingly irreconcilable obstacles. Firstly, the shores were extremely low (and of asymmetric heights) from which it was necessary to allow direct access to the bridge, secondly, the demand for a greater height of the bridge construction due to the flood risk of the river, and thirdly, the demand for a maximum 6% slope, allowing bridge crossing also to the disabled people. To achieve these goals we found an innovative construction design concept with a variable cross-sectional geometry of the bridge.
The result seems simple but is in fact a complex and dynamic spatial form, which can only
be realized using up-to-date technology and computer-assisted designing. It is a visual
language indirectly speaking about the time in which the object was built. The bridge is thus
dematerialized with lyrically softened lines of its elements and the choice of light blue color
(RAL-7035), which additionally takes away its tectonic quality. In this way it becomes an abstract idea, a symbol and a new icon of the town. Bridges in light colors give an airy, sunny and lightweight feel. In a desire to preserve the night panorama of the town, or rather, to retain an unobstructed view of the starry sky, the bridge lighting is provided only by LED lamps concealed under the fence ledge. The only exception being the discreet lighting of
the bottom bridge span, itself of unique shape, thus creating a recognizable image also in
the night panorama of the town. Pedestrian surface is designed similarly to a sailboat deck,
slightly arched and protected from the river with a fence, giving it a nautical feel.
THE GEOMETRY OF THE BRIDGE
The footbridge is shaped as a slightly tense steel bridge beam with a varying cross section,
which extends from Savinja embankment to the deepened Partizanska street in a single span
of 73 meters, crosses the street in the span of 8 meters and lowers towards the level of town
park in the shape of a spiral, which is 26 m high and 24 m wide. In the longitudinal section
the steel beam has a varying height, rising from 70 cm at the bed on the left bank to 1.64 m
at the crown of the structure in the middle of the river and is growing thinner towards the
supporting walls along the Partizanska street, where it reaches the height of 70 cm again.
From there the footbridge continues to the shape of the spiral, where the beam is only 30
cm high. At the end of the spiral a monolithic wedge-like concrete conclusion is made. The
bridge beam cross section (a box structure made of thick steel sheets) is of trapezoid shape.
It measures 3.30 cm on the upper side, while on the lower side its width varies depending on
the characteristics of the longitudinal section and measures from 1.39 m at the crown of the
bridge, to 2.95 m at the spiral. Due to the chosen geometry of cross sections the bridge will
seem lighter than the usual beam constructions.
On the left bank the bridge is fastened into a heavy foundation on deep-seated piles, on the
right bank it is fastened into a box-shaped AB frame, formed by two supporting walls along
the Partizanska street and are placed on underlying concrete slab, lying above the found
archeological level under the Partizanska street. Ending of the bridge in the park in the form
of a spiral is supported by thin round steel columns joints.
