Method for predicting accumulated adsorption of water in expansive soil

The invention discloses a method for predicting accumulated adsorption of water in expansive soil, wherein the method comprises the steps: S1, selecting an adsorption process of water in the expansive soil as a research object, and determining to carry out a water adsorption test to obtain test data of accumulated adsorption of water; S2, establishing a fractal derivative diffusion fluctuation model of expansive soil moisture adsorption according to material coordinates; S3, combining a fractal derivative diffusion wave equation to deduce a water accumulation adsorption amount equation in the expansive soil; S4, in combination with test data of water accumulation adsorption, through data fitting, obtaining a value of an order alpha of a time fractal derivative and a value of a diffusion coefficient Dm, and classifying the adsorption process of water; and S5, substituting the parameters alpha and Dm into the water cumulative adsorption quantity equation, and predicting the water cumulative adsorption process i