piling = putting?

Context:

That winter, however, he surprised technology observers by announcing that he’d accepted an appointment to the MIT Media Lab for the following spring. Despite a cut in pay, he’d have to work longer hours, piling administrative and teaching duties on top of his research. But to Raskar, the move made sense.

More:
http://web.mit.edu/newsoffice/2011/profile-raskar-0929.html