the process that describes downward sliding of the rock material is Slump
A shear breaks off or crumbles. A slump stays together however it will slump down.
Topical
Slump is to slouch or collapse. For example, you could slump into a chair.
If you mean a soil slump then no, adding mass to the head (top) of the slump will likely increase the likelihood of failure. If you are to add mass it should be added at the toe. However if you want to stop a slump moving the best thing you can do is to drain the area.
Type of slump test are,True slumpShear slumpCollapse slump
Don't slump, you'll injure your spine.There was a big slump in sales.
a sweeping motion
your mother
Words that imitate the sound of what they describe - APEX
Paranoid, looking for a way out
balance or harmony