Abstract: In order to investigate the relationship among stress, strain and strength of soil under unsaturated moistening, water content is introduced into the hardening parameter of Tsinghua model to develop the Tsinghua elastoplastic model of unsaturated soil. On the basis of moistening tests by means of mixing ice crumblings into dry soil, it is shown in the test results that this model is capable to predict the relationship among stress, deformation and the strength of unsaturated soil under different water contents. The results of model calculations well agree with the test results of soil moistened from the air-dry state to other unsaturated states corresponding to various water contents. With water content directly introduced into the elastoplastic model instead of the complicated matrix suction, it might be showing a handy and explicit way to the engineering application of unsaturated soil constitutive models.

Key words: water content, elastoplastic model, unsaturated soil, moistening, matrix suction