DYNAMIC CHARACTERISTICS OF ALKALI SLAG CURED LIGHTWEIGHT SOIL UNDER ACTION OF DRY AND WET FREEZING AND THAWING

This paper aims to study the effect of complex climatic conditions on the dynamic properties of alkali slag cured lightweight soils. Dynamic triaxial tests were conducted for alkali slag cured lightweight soils under the action of dry and wet freeze-thaw coupling. The test results show the follows. The cumulative strain curve of alkali slag cured lightweight soil exhibits three different forms,i.e.,stable,critical and destructive. The axial strain of cured soil increases with the increase of the number of dry and wet freeze-thaw coupling and the decrease of the freezing temperature,among which the effect of the first three times is greater,and basically reaches stability after five times. According to the axial strain law of cured soil,the cumulative dynamic strain prediction model is established. With the decrease of the freezing temperature,the dynamic strength of alkali slag cured lightweight soil gradually decreases. As the freezing temperature decreases,the dynamic strength of alkali slag cured lightweight soil gradually decreases,and the trend of decrease is faster and then slower,and finally stabilizes. With the increase of the number of wet and dry freeze-thaw cycles,the rate of decrease of dynamic strength is faster and then slower,and the decrease of dynamic strength is larger in the first three times,and the change is smaller after five times. Combined with the development law of dynamic strength,the relationship among the number of wet and dry freeze-thaw coupling,freezing temperature and dynamic strength is proposed,which can provide some theoretical guidance in the practical application of engineering. This paper provides some theoretical guidance in practical engineering applications.