Case Study

Design and reconstruction of Suyeong Bridge No. 1

• Stylish 3-span steel box girder road bridge

• Replacement for 3 existing bridges

• Linear and dynamic analysis

ENVICO Consultants used LUSAS Bridge for an alternative design of the Suyeong Bridge No. 1 in Busan, South Korea, on behalf of Lotte Engineering & Construction Co., Ltd. The new bridge replaces three previous bridges that crossed the river at this location that required replacement for traffic flow and appearance reasons.

Suyeong Bridge No. 1 is a 3-span continuous steel box girder bridge that carries pedestrians and a pair of 4-lane carriageways across the Suyeong river from Millak-dong, Suyeong-gu to U-dong Haeundae-gu. The stylish new bridge is 180m long and has a central span of 85m and two side spans of 47.5m. The width of the bridge is 45m, comprising 20m wide spans with a 5m central gap between each span. Four main steel girders, varying from 3.5m to 2.2m in depth, support a continuous steel deck. Cantilevered pedestrian walkways with viewing areas are supported by a steel tube strut system. Costing 47 billion Won, the construction of the new bridge started in June 2004 and it opened for full use on 3rd February 2008.

Using LUSAS Bridge analysis software, thick beam and thick shell elements were used to create two models: one for a 3D linear static analysis and one for a separate seismic analysis.

Chang Moon of ENVICO Consultants said: "LUSAS analysis was required on this project because we had to get section forces of girders and reactions at supports in the most efficient manner possible." He added: "we needed to use software that provided easy-to-use modelling facilities and also gave us accurate results."

Of particular use to ENVICO Consultants was the ability to define any type of bridge loading and the extensive load combination facilities in LUSAS. Also of great importance on this project was the ability to define and modify varying section properties along the length of each span. From the static and dynamic analyses carried out, section forces, reactions, and displacements were obtained allowing Envico to optimise and prove the design.

Construction company: Lotte Engineering & Construction Co., Ltd.
Structural Designer: ENVICO Consultants, CHEIL Engineering Co., Ltd.

Bridge location

Completed bridge