They do that with almost all of them once a job is done.A little known fact, when they were boring the Eisenhower tunnel their machine started to fail, they did a cost analysis and decided to bore off to the side and abandoned it. Brought in another machine and finished the job. It's still there today.
It's cost prohibitive to take it apart and try to use it somewhere else; each machine is designed for that specific job.
So they bury them on site. (If they have the space to do it)