How to evaluate the effects of soil structure on mechanical behavior for natural sedimentary soils is an important issue in geotechnical engineering. Burland has introduced void index in the Thirtieth Rankine Lecture for normalizing the compression curves of various reconstituted soils

and proposed the intrinsic compression line for assessing the in-situ compressive behavior of natural sedimentary soils. In this study

a series of tests were performed for natural sensitive Ariake clays deposited in Japan to investigate the engineering properties. Based on the extensive experimental data

it is found that the void index proposed by Burland has an unique relationship with a simple physical index

designated as normalized water content. The normalized water content is defined as the ratio of water content to liquid limit. The intrinsic compression line (ICL) proposed by Burland is rewritten in the simple form of the normalized water content and against the applied pressure.