Why do plastic bins keep cracking at the base?

[jacintocollier]

We have gone through four plastic garbage containers at our warehouse in Sharjah in the last two years and they all fail the same way, cracking at the base or along the bottom edge where it meets the wall. Not from overloading, we do not stuff them crazy full. My theory is the guys drag them instead of lifting when they are heavy, and the base takes all the stress. But maybe it is the plastic itself, or the heat, or the fact that the floor is uneven and rough concrete. I am tired of replacing them every few months and wondering if I am missing something, like a specific type of plastic that handles dragging better, or a design with a reinforced base. Is there even such a thing or should I just accept that bins are consumable at this rate. Would rather hear from someone running a similar dusty rough floor operation than keep buying the same mistake.