Hyundai E&C, which is in charge of the construction of the site for the new airport in Gadeokdo, emphasized again that the construction period needs to be extended by 2 years for safety. The government and Busan city previously expressed their position that they could not accept Hyundai E&C's basic design plan, which extended the construction period to 108 months (9 years).
Given that it is essentially a massive and challenging construction project to build an airport more than twice the size of Yeouido over the sea, and considering the extremely weak ground conditions at the site, it is known that Hyundai E&C's position is that the 84-month (7 years) construction period proposed by the authorities cannot guarantee safety.
According to industry sources on the 6th, Hyundai E&C is preparing specific reasons and related explanatory materials for the construction period to submit to the government based on this position, and is expected to submit them within this week.
Earlier, the Ministry of Land, Infrastructure and Transport requested Hyundai E&C to submit reasons for the difference in construction period presented from the bidding announcement while directing revisions to the 108-month basic design plan on the 28th of last month.
Hyundai E&C is expected to emphasize that the scale and difficulty of the construction must be reflected in the construction period. The new airport in Gadeokdo is a massive project that involves constructing runways and related facilities over an area of 2.9 square kilometers.
To accomplish this, work must be carried out to solidify the weak ground under the sea, and construction to relocate mountains and reclaim land from the sea must also take place. This process includes blasting a mountain peak, equivalent to three times the size of Namsan (15 million cubic meters), to produce 23 million cubic meters of earth and stone.
Hyundai E&C explained that this project is the largest offshore airport construction project ever and that it carries an unprecedented level of difficulty in terms of work environment for South Korean construction companies.
Recently, accidents such as ground collapses have frequently occurred at construction sites, highlighting the necessity of adhering to safety quality requirements even within these extreme construction environments.
In particular, the area surrounding the project site is located in a region where waves can reach 12 meters during typhoons, making it essential to apply safety construction methods that can withstand typhoons and high waves.
To this end, Hyundai E&C plans to install caissons (hollow concrete structures) to block high waves and then proceed with land reclamation. Accordingly, an additional period of about 7 months is required for the placement of these caissons.
Hyundai E&C believes that the improvement of the seabed's extremely weak ground, which reaches a maximum depth of 60 meters, and the land reclamation at depths of 25 to 70 meters, equivalent to a 25-story apartment, should also be factored into the construction period estimation.
Additionally, construction is needed to ensure stability in the seabed layer of the runway section to prevent ground subsidence due to the clay layer used in weak ground improvement and the reclaimed structures. It is also estimated that 18 months will be required for work related to the runway, a critical facility that must withstand aircraft taxiing loads and landing impacts.
Regarding the extended construction period of 108 months, Hyundai E&C stated that this was the result of design reviews conducted by about 250 specialized personnel in the fields of airport, port, and design over about 6 months.