DL E&C Completes Installation of All Caissons for Ulleung Airport, Laying the Foundation for the Runway

Precision Construction Over Three Years, Runway Foundation Completed with Structures Withstanding 22.6m Waves
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DL E&C announced on May 8 that it has completed the installation of all 30 caissons for the construction of Ulleung Airport. The caisson is a key structure for forming the reclaimed land for the runway. With the completion of this installation, the runway foundation work has entered its final stage.

Caisson installation at Ulleung Airport. Provided by DL E&C.

Ulleung Airport is the first airport in South Korea to be built on an island. Considering the geographical characteristics of Ulleungdo, where it is difficult to secure flat land, a method of reclaiming the sea to create the runway was adopted. In this process, DL E&C applied the caisson construction method to airport construction for the first time in South Korea.

The caissons installed this time measure up to 28 meters in height, 32 meters in width, and 38 meters in length, with a weight of 16,400 tons. Starting with the installation of the first caisson in May 2022, all 30 units were installed over approximately three years. The exterior of the caisson is designed in a "wave energy dispersion" honeycomb structure, and the curved shape provides durability to withstand a maximum wave height of 22.6 meters, which corresponds to a once-in-200-years event.

The caissons were manufactured at Yeongilman in Pohang and transported about 210 kilometers to Ulleungdo by tugboat. This marks the longest caisson transport distance by sea in South Korea. During transportation and installation, a special piece of equipment called the "IPCCV" was used for dock movement and marine loading. Marine operations could only be carried out when the wave height was 1.5 meters or less, so precise process management was required, taking into account the limited workdays of 10 to 15 days per month. After installing the caissons, DL E&C filled the internal space with about 60,000 tons of rubble, and divers performed manual work to fill the gaps, ensuring precise construction.

Ulleung Airport is being built on a site of about 430,000 square meters in the Sadong Port area of Ulleung County, North Gyeongsang Province, with a total project cost of 607.3 billion won. DL E&C is carrying out the project as a turnkey contract, handling everything from design to construction. Since construction began in July 2020, the project is currently 61% complete. The airport is scheduled to open in 2028. Once the airport is operational, travel time between Seoul and Ulleungdo will be reduced from the current seven hours to about one hour, greatly improving transportation accessibility.

A DL E&C official stated, "Even under extreme conditions, we are proceeding with construction without any setbacks, based on advanced technology and precise execution," adding, "We will continue to prioritize safety and quality in completing the remaining work."