The collapse index Ie of a soil can be determined by applying a vertical stress of 200 kPa (2 tsf) to
the soil specimen, submerging it in distilled water, and then determining the percent collapse by
using (Eq. 7.1 or 7.2), which is designated the collapse index Ie. This collapse index Ie can be considered
as an index test to compare the susceptibility of collapse for different soils. The collapse
index Ie versus degree of specimen collapse has been listed in Table 7.1.