Digging in your tank was a common tactic in WWII armoured warfare, both as a method of concealing a group of tanks at an assembly point or as a part of a line of defense, if keeping your tank's vulnerable area to a minimum was more important than mobility. In this case, since an immobile tank is a dead tank, there were usually reserve locations where the tanks could move to if they were threatened from the air.

In German notes on Eastern Front armoured warfare in 1942, they write:

Russians use 2-3 dug in, well hidden tanks to cover their retreat. The positions of these tanks are picked to allow them to protect their flanks

The Germans themselves didn't seem against using the tactic themselves:

Commanders of supporting artillery are responsible for the success of the tank attack. Moving out artillery past the front infantry lines is unacceptable. In exceptional cases, it is permitted to use dug in tanks.

Some tanks were better than others for this kind of tactic. For instance, the Soviets complained that the Lee was unsuitable for being dug in, since its main gun was in the hull and thus was unable to fire.

The practice of removing tracks and suspensions from tanks and digging them in permanently was also common, but it was more of a peacetime thing when building fortifications. Many nations did this, and a number of rare tanks in museums today were saved from the scrap heap by being dug in this way.

P. Samsonov German Experience

P. Samsonov 107th Independent Tank Battalion

P. Samsonov Lend Lease Replacement

P. Samsonov Dig In

P. Samsonov Tank Corps on the Defense