Most tunnels are a shell with an outer shell to accommodate ventilation and maintenance access, as well as to offer more rigidity with less material. What bothers me here is that usually such elements of critical infrastructure get an inspection after an earthquake. One might expect a "wounded" structure to fail in a succeeding event, but one would think the inspection sufficient to determine safe operating conditions under a static load given the usual safety factors.
This is just weird.
Well, it’s not like their inspectors and engineers haven’t had anything else to do in the last few years after the tsunami. Perhaps they had to delay the inspection to deal with what they thought was more important during the tsunami recovery.