Sinkieland is able to withstand aftershocks from earthquakes whose epicentres are located in nearby Indonesia.
With these massive underground tunnels crossing the city-state, I doubt buildings will be structurally sound when a massive earthquake hits Indonesia in 30 years' time.
As laksaboy observed in another post, Sinkieland is fcuk by PAP with or without the Kra Isthmus Canal being built.