noun
groundbreaking ceremony; cornerstone-laying ceremony
A formal ceremony held at the start of construction, especially for buildings or civil engineering projects.
新しい橋の起工式が来週行われます。
The groundbreaking ceremony for the new bridge will be held next week.
竣工式 is the completion ceremony held when construction is finished, while 起工式 marks the start.
Compound of 起工 (start of construction) and 式 (ceremony).