The traditional theory of soil mechanics considered that the preconsolidation of soil was controlled by the pressure force and stress history. However

based on the experimental results

the rule of the preconsolidation of red clay that is territorial peculiar soil is different from the traditional theory. The studies show that

the preconsolidation of red clay is most constrained by soil genesis

structure and component

and is affected by the overlying pressure in little degree. Finally

the defect of traditional soil mechanical view on red clay is analyzed; and the genuine signification of preconsolidation pressure of red clay was studied; and the new understanding about the preconsolidation is presented.