Cycle bridges of Lake Tisza

CYCLE BRIDGES OF LAKE TISZA

Edited by SPECIÁLTERV SPT-TIS-V2-2305

NOTES BY THE DESIGN TEAM

We were commissioned to design a cycle route including many water crossings in 2017. The lake provided a unique context - the process of creating a bridge involved a careful balance between form, function and sustainability. Starting with a thorough analysis of the site and the needs of those who will use the bridges, we explored a range of design options before settling on a solution that is both structurally sound and visually appealing.

The bridges were designed by Gábor Pál and managed by Tibor Borzai in all design phases from conceptual design until their realization in 2020.

The bridges have since became popular tourist attractions and landmarks to the lake itself. They were recognized by prestigious professional associations and received a number of prestigious awards:

Steel Structure of the Year Award 2020 (Eger Bridge)

MAGÉSZ Hungarian Steel Structures Association

Cycle Route of the Year Award 2021 Association of Traffic Sciences. Hungary

I. Prize - FIABCI Hungarian Prix

d’Excellence 2022

Public Infrastructure / Amenities category

II. Prize - FIABCI World Prix

d’Excellence 2023

Public Infrastructure / Amenities category

Cover image: Zoltán Szabó, SPECIÁLTERV

POROSZLÓ

EGER CREEK BRIDGE

SZOMORKA CREEK BRIDGE

LAKE TISZA

CANAL NO. X. BRIDGE

TISZA BRIDGE

SERVICES

Multi-disciplinary design in all stages of the project

Conceptual, permit, tender and construction design

Bridge & structural design

Cycle road & infrastructure design

Utility & drainage design

Geotechnical analysis

THE PROJECT

We have developed a 7.3 km long new cycle route with four unique bicycle bridges.

The new route is the final section of the 65 km cycle route around Lake Tisza. The new corridor provides a safe link for tourists and locals between the two prominent cities of the region.

The development has greatly contributed to boosting conventional tourism and eco-tourism in the Lake Tisza area.

THE SHAPE OF THE BRIDGES HAS A SYMBOLIC VALUE - THE WAVE FORM REFLECTS THE WAVES OF THE LAKE AND THE VIBRATIONS OF THE ENVIRONMENT

CONTEXT

Lake Tisza is a 127 km2 lake located in Eastern Hungary.

It is the largest artificial lake in the Carpathian Basin. It was created as a reservoir on River Tisza in the 1970s.

Over the last 50 years it became a unique nature conservation area and a Natura 2000 bird sanctuary.

BEING PART OF THE FAMOUS HORTOBÁGY

NATIONAL PARK, IT IS A UNESCO WORLD HERITAGE SITE SINCE 1999.

7,3 km designed cycle route

65 km continuous cycle route around Hungary’s largest artificial lake

Canal No. X bridge

Tisza bridge

Szomorka Creek Bridge

Eger Creek Bridge

Image: Google

DESIGN FOR A POSITIVE CHANGE

Completing the circle around the lake was a pressing undertaking with the steadily increasing demand for an extensive and safe cycling network around Lake Tisza.

The construction of the bridges has brought about a striking increase of users.

In the years following the completion of the route, registered bicycle traffic around the lake nearly doubled.

EGER CREEK BRIDGE

Embodied carbon savings with smart design Infrastructure development for sustainable micro-mobility and active recreation

765 x

Lake Tisza

It was one of our priorities to design the bridges with smart, material-effective solutions.

Opposed to regular construction technologies, innovative methods and thorough prior research helped us develop more sustainable designs that significantly reduce the embodied carbon & construction-related CO2 emissions while minimizing the impact on the fragile

2000 habitat.

solutions: 1. girder bridge with 12 additional supports; 2. girder bridge wirh 4 additional supports; 3. construction of substructures in the riverbed; 4. 90 long high driven girder bridge on new substructure

DESIGN FOR THE HUMAN SCALE

As a result of the development, the number of cyclists visiting the natural environment has multiplied.

Lake Tisza and its surroundings belong to a less developed region of Hungary - the new infrastructure has also granted the opportunity of economic growth for settlements along the route.

Image: MTI, Zsolt Czeglédi

Image:Miklós Tóth

Image: Péter Gyukics, SPECIÁLTERV

Image:

Span: Span: Span:50,72

Length of superstructure:

superstructure:

Span: Span: Span: Span:

PARAMETERS EGER CREEK CYCLE BRIDGE

Location: Lake Tisza, HU

Status: Complete

Material: Steel

Function: Cycle bridge

No. of spans: 8

Surface: 923 m2

Length: 308 m

Main span: 51 m

Structure: Series of arch bridge

EGER CREEK CYCLE BRIDGE

A unique landmark bridge design was created for the longest of the four bridges. With a continuous sinusoid arch form, it creates a symbolic connection with its surroundings - the white arches are a continuation of a sinusoid wave.

The structure is a 308 m long eight-span continuous arch bridge, with semi-integral substructures and a steel box girder deck of 3.71 m width and only 60 cm depth. Up to our knowledge, it is the longest continuous wave-shaped bridge in the world.

Its form was rendered feasible due to an innovative engineering solution between the arch and the supports. The pillars of the bridge are connected to an arch tube, and not directly to the deck.

This was achieved with a smart solution - a connection which functions just as a gripping hand, providing the required torsional strength for the entirety of the superstructure.

Cross-sections of the tie girder on a normal and a widened section

Finite element model of the unidirectionally moving pipe girder’s tie down

Design concept for the connection of the arch tube and the pillars

General cross-section

Image: Péter Gyukics, SPECIÁLTERV

Image: Magyar Építők

Image: Zoltán Szabó, SPECIÁLTERV

Total structural length

Superstructure span width

Substructure span width

Span:

Span:

Span:

Span:

SZOMORKA CREEK BRIDGE

PARAMETERS SZOMORKA CREEK CYCLE BRIDGE

Location: Lake Tisza, HU

Status: Complete

Material: Steel

Function: Cycle bridge

No. of spans: 3

Surface: 300 m2

Length: 80 m

Main span: 47 m

Structure: Continuous arch bridge

SZOMORKA CREEK CYCLE BRIDGE

Szomokra Bridge is a 86.3 m long three-span bridge, which inherits the wave form from its neighbour. While it has slightly different span proportions, it has the same architectural identity and structural details as the Eger Creek Bridge.

The verification of these unique bridges was performed with finite element modeling and load testing on the completed bridges.

Szomorka Creek Bridge is a steel half-through arch bridge with an orthotropic box-girder deck with four supports and 19.25 + 47.40 + 19.25 metre long spans. The total length of the superstructure is 86.30 metres.

General cross-section

Spatial model of the pillar’s contour reinforcement Design concept for the pillar

Image: Miklós Tóth

Image: István Wunderlich

Total structural length

Superstructure span width

Substructure span width

TISZA RIVER BRIDGE

Photo: Zoltán Szabó, SPECIÁLTERV

Image: Zoltán Szabó, S PECIÁLTERV

PARAMETERS TISZA CYCLE BRIDGE

Location: Lake Tisza, HU

Status: Complete

Material: Steel

Function: Cycle bridge

No. of spans: 5

Surface: 300 m2

Length: 279 m

Main span: 70 m

Structure: Continuous arch bridge

Design for sustainability - the new cycle bridge was constructed without disturbing the riverbed’s ecosystem

TISZA CYCLE BRIDGE

Tisza Bridge is a series of 5 arch bridges with orthotropic steel decks. The wave motif also reappears here; the two side-spans are arched truss structures, while the mid-spans over the riverbed are tied-arch bridge structures.

The designed bicycle road bridge over Tisza is supported by cantilevered reinforced concrete beams of the existing stone-covered concrete piers. Extension of the pier caps were built by jacketing and forming new reinforced concrete cantilevers. Therefore, there was no need to build new foundations into the riverbed.

The new concrete structures were fixed to the existing pier caps with post-installed reinforcement bars and by pressing the new reinforced concrete jacket onto the old surface with transversal post-tensioning.

Finite element model of the arc shoulder and end cross girder

Conceptual model of the Tisza bridge widening

Image: Péter Gyukics, SPECIÁLTERV

Image: Péter Gyukics, SPECIÁLTERV

Image: Zoltán Szabó, SPECIÁLTERV

Span:

PARAMETERS BASCULE BRIDGE

Location: Lake Tisza, HU

Status: Complete

Material: Steel

Function: Cycle bridge

No. of spans: 1

Surface: 30 m2

Length: 6 m

Main span: 5 m

Structure: Bascule bridge

CYCLE BRIDGE

Bridge Canal No. X is Hungary’s first openable cycle bridge. The canal is 90 m wide - the originally planned bridge was imagined to be of a respectively large length and height.

Instead, we proposed a solution that integrates the existing dam structure with a superstructure that could be opened - which also proved to be an economically advantageous solution for our client.

The cycle bridge is a structure with a liftable counterweight by human power - its movement is enabled by worm gear and the attached chain drives. When it is opened, a lockable counterweight machine fixes the structure.