Log–normal, normal, exponential, gamma, and
Weibull distributions were fitted to the joint spacing
frequency distributions for each joint type in each
weathering grade Table 5.. Unless otherwise noted,
results reported in this section are at the 90% confidence
level. For horizontal joints in SW, MW, HW
and CW granite, any of the five distributions except
gamma could fit the data. None of the five distributions
fit the horizontal joint spacings in fresh granite.
Furthermore, there were no good fits for vertical
joint spacings in HW and MW granite or in fresh
granite. Vertical joint spacings in CW granite could
exhibit either log–normal or exponential distributions and spacings in SW granite could belong to
either exponential or Weibull distributions.
The K–S statistic was used to determine whether
the joint spacing frequency distributions were statis-
tically similar or dissimilar Table 5.; Fig. 8 shows
examples of the distributions for each joint type. All
combinations of distributions for each joint type are
significantly different from each other.