  Compressive strength is a key to understanding the internal structure of dust
aggregates in protoplanetary disks and their resultant bodies, such as comets
and asteroids in the Solar System. Previous work has modeled the compressive
strength of highly-porous dust aggregates with volume filling factors lower
than 0.1. However, a comprehensive understanding of the compressive strength
from low ($<0.1$) to high ($>0.1$) volume filling factors is lacking. In this
paper, we investigate the compressive strength of dust aggregates by using
aggregate compression simulations resolving constituent grains based on JKR
theory to formulate the compressive strength comprehensively. We perform a
series of numerical simulations with moving periodic boundaries mimicking the
compression behavior. As a result, we find that the compressive strength
becomes sharply harder when the volume filling factor exceeds 0.1. We succeed
in formulating the compressive strength comprehensively by taking into account
the rolling motion of aggregates for low volume filling factors and the closest
packing of aggregates for high volume filling factors. We also find that the
dominant compression mechanisms for high volume filling factors are sliding and
twisting motions, while rolling motion dominates for low volume filling
factors. We confirm that our results are in good agreement with previous
numerical studies. We suggest that our analytical formula is consistent with
the previous experimental results if we assume the surface energy of silicate
is $\simeq210\pm90\mathrm{\ mJ\ m^{-2}}$. Now, we can apply our results to
properties of small compact bodies, such as comets, asteroids, and pebbles.
