Perhaps the most practical is that it compensated for the settling of the grave. Before burial vaults, when coffins were made of wood, the coffin would eventually collapse in on itself, leaving a depression at the grave site. Mounding was protection against that.

What does it mean when grave sunken?

Grave subsidence refers to the appearance of graves 'sinking'. This is an entirely natural process caused by loosened soil settling into place and the natural process of the coffin collapsing overtime.

Why are graves dug back up?

It might have been for the safety of the gravedigger, or to make grave digging easier. People may have also believed it would keep bodies from being disturbed or prevent the spread of disease. ... Generally speaking, most graves dug today are only about 4 feet deep.