Strengthened Seismic Design Requirement: Is it Challenge or Opportunity?
Seismic design requirements were introduced for the first time in Korea in 1988 for buildings 6 storeys and higher or total floor area 100,000m2 and larger. The latest major revision was made in 2005 requiring building structures 3 storeys and higher or total floor area 1,000 m2 to be seismically designed for safety and in 2015, a minor change was made to restrict the total floor area to 500 m2.
Korea has long been regarded as a safe country from earthquakes. However, a record-breaking 5.8-magnitude earthquake took place in September, 2016 in Gyeongju and over four hundred smaller aftershocks have triggered public concern and MLIT promulgated a strengthened seismic code in February, 2017 to bolster seismic design in all new buildings 2 storeys or higher and larger than 500 m2 from the former 3 storeys or higher.
After the 5.4-manganite earthquake happened in November, 2017 in Pohang, MLIT further strengthened the seismic design requirement to larger than 200 m2 and to all newly built houses (all newly constructed single detached homes and apartments) regardless of the total floor area and enforced this requirement in December, 2017.
As the seismic design code being strengthened and people’s fury on earthquakes increased, there are more opportunities for wood frame construction in Korean construction market as it has been experienced in Japan.
However, given the lack of trained architects and structural engineers, providing seismic design for individual wood frame buildings would is challenging. In the short term, this new regulation is impacting the WFC market considerably since there is no building code guidance available for small timber construction as opposed to concrete, brick and steel which are more conventional structural systems in Korea and already included in MLIT’s Small Scaled Construction Structural Code (SSCSC) for up to 2 storey buildings.
Current efforts to create a prescriptive code, thereby allowing design without structural calculation by licensed structural engineer, should diminish the risk of a loss of market share due to a lack of design capacity and design guide.
In parallel with prescriptive seismic design code development, Canada Wood Korea is providing a series of workshops on seismic design for wood frame construction in a response to the revisions related to the increased interest in seismic design.