Abstract: Through two group tests on clayey soils with different water contents under Quick-soaking, slow-soaking, freezing-thawing, different stresses; the following studies were performed: the relationship between mechanical strength and microstructure dynamic environmental energyfield of clayey soil; the interrelation between the microstructure dynamic environmental energyfield; changing of external environment and medium environmental intrinsic of clayey soil. The results show that the water soaking is vital to microstructure, its influence on shear strength is higher than it on deformation properties of clayey soil obviously; when number of blows of more wet and vibrated soil increased, the damage of initial construction increased, but the later strength of construction increased for a little. Analysis indicates that the freezing-thawing is most important to failure of microstructure of soil; the second is slow-soaking.

Key words: clayey soil, microstructure, dynamic environmental energy field, mechanical strength properties