Circular motion

The expansion joints we supply for bridges and buildings must typically be designed to facilitate some degree of transverse movement of the superstructure – generally much less than the longitudinal movement – but the two-level Geumgang Pedestrian Bridge in South Korea, with its circular shape, required expansion joints that will accommodate an unusual combination of movements.

Sejong City in South Korea was founded in 2007 with the objective of making it the country’s administrative capital within just a few decades. When construction of this planned city is completed – scheduled for 2030 – it is expected that all of South Korea’s main government institutions should be moved to Sejong. This will reduce pressures relating to land use, traffic, etc. in South Korea's largest city, Seoul, and promote the economic development of another part of the country.

An important connection has now been created across the Guam River, which dissects the city, with the completion in early 2022 of the construction of the spectacular Geumgang Pedestrian Bridge. With its circular shape, and its design features that are intended to make its use a pleasant experience for the pedestrians and cyclists that share its two levels, it has already become a popular visitor attraction and a city landmark.

The bridge has a steel pipe truss design and a total length of 1650 m, making it the longest pedestrian bridge in South Korea. The superstructure’s circular shape, and the locations of its fixed points in relation to its expansion joints, resulted in the unusual requirement for some of the expansion joints to be able to accommodate transverse movements that are just as large as their longitudinal movements. Thanks to its exceptional flexibility, with the ability to be designed to facilitate large movements in any direction and rotations about any axis, mageba’s TENSA®MODULAR expansion joint was selected for use. The required joints were designed by mageba to meet all requirements, fabricated at the company’s Shanghai production facility, and transported to site in closed shipping containers. After arrival, they were installed to facilitate the superstructure’s movements at both levels – the upper pedestrian level and the lower bicycle level – with the installation process supervised by mageba’s local South Korean experts.

While we are always happy to facilitate the construction of such special structures, we are equally happy to know that they will hardly be noticed as they quietly serve their vital purpose in the coming decades. The bridge’s users and visitors will be able to enjoy the structure without being hindered by expansion joint repair or replacement works, and will be able to ignore these critical components as if they weren’t there – the perfect result, also from our perspective. 

Bridge designer: Dasan Consultants Co., Ltd.
Contractor: Lotte Engineering & Construction
Owner: Korea Land & Housing Corporation

The Geumgang Pedestrian Bridge in Sejong City, South Korea’s planned administrative capital, is a steel pipe truss bridge with a total length of 1,650 m

The two-level structure has cycle lanes on the lower level and pedestrian areas on the upper level

The new bridge has already become a spectacular addition to the local cityscape and a popular visitor attraction – while also providing a vital transport connection across the Guam river

Unloading of a TENSA®MODULAR expansion joint following shipping to site in South Korea from mageba’s Shanghai factory

Lifting a three-gap TENSA®MODULAR expansion joint into position at one point along the circular superstructure

A TENSA®MODULAR expansion joint following positioning in the provided recess in the superstructure, ready to be secured in place before filling the recess with concrete

View of one expansion joint following completion of installation in the bridge’s lower deck to serve predominantly cycle traffic