Gwangyang Bridge Korea

The Gwangyang Bridge will connect Gwangyang City through Myodo Island to Yeosu city, in Korea. This bridge is to be completed by June, 2012, coinciding with the Expo Yeosu Korea 2012 and its construction is intended to improve investment in the Gwangyang Bay area and to boost tourism for the Expo. Gwangyang Bridge, also known as "1545 Bridge", will have a main span of 1545 m in honour of a famous Korean sea hero, Admiral Sun-Shin Lee, born in 1545. With symmetrical side spans of 358 m, the total length of the bridge is 2260 m and the concrete H-shaped towers stand 270 m high. The clearance of the bridge is 85 m.

TDV was approached by Daelim Industrial Co. in Korea to assist in this project.

Gwangyang Bridge, Suspension Bridge

The deck has been designed as a twin steel box girder with stiffening girders, similar to the design used on the Stonecutters and Sutong bridges. The construction of the main deck will be done following the so-called “Japanese way”, which means that adjacent deck segments are connected by hinges before welding. Each segment is connected to the main cables only by one hanger. After welding the final shape is therefore allowed to have kinks with this construction technique.

Special attention was paid to the modelling of intermediate connections with hinges as well as the built-in construction kink in the final structure. These modelling aspects were combined with a highly nonlinear form finding procedure to obtain the optimum stress free cable lengths for main cables as well as hangers. The detailed construction sequence was fully included into the analysis to obtain insight to the real segment positions at each stage of construction. As part of this optimization process the modelling of moving saddles of the main cables was outlined.

TDV was part of the Consultant team and mainly responsible for the numerical simulation of the construction stage analysis, the full modelling and the structural analysis of this complex structure.

The principles of the Construction Sequence are given below:

• The concrete towers are erected first;
• The main cable is installed;
• The deck girders will be lifted at the side spans and swung into their final position using specially-designed gantries running on the main cables. This will enable the shipping span to be kept open throughout the erection process;
• The segments are welded and the super imposed dead load is applied.

Gwangyang Bridge, Form Finding Process

The form-finding process – i.e. determining the theoretical “stress-less” state of the structural components – is a backward iteration process, being rather complicated and time consuming if done in the conventional way. As an alternative to the conventional approximate hand calculation, the Additional Constraint Method has been provided in the program RM Bridge V8i in order to find and optimize the shape of the suspension cables and the hangers of Gwangyang Bridge.

The assistance given by TDV for the Gwangyang Bridge project was in deriving a concept for the erection procedure and providing the know-how and expertise for the final stage and the construction stage analysis.

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• Contract:
  • Gwangyang Bridge Korea.
• Consultant:
  • Daelim Industrial Co., Korea.
• State of Construction:
  • Under construction.
• TDV Involvement:
  • General advice on erection procedure and construction stage analysis;
  • Full numerical modelling and non-linear structural analysis for Construction Sequence;
  • Optimization of construction sequence and free cable lengths;
  • Full deck pre-camber/erection design;
  • Full erection control.

TDV Consulting GmbH
Dorian Janjic & Partner
A-8010 Graz, Austria