That’s mad that is.
What’s the economic reason for connecting them? I can understand the need to connect Europe to the UK – massive amounts of trade flow between them. If they want to move oil, then build a pipeline but I’d need more convincing about the need for a train link.
Technically it should be buildable though. The Straits are quite a way from the Tectonic plate boundaries. NE Siberia and Alaska are actually on the same plate – different continents but the same Tectonic plate. The boundary between that plate and the Pacific plate is further south, along the line of the Aleutians – that’s where all the earthquakes are.