Determination of expansive soil strength using a fractal model

The micropore surface fractal, model for expansive soils is proposed in thi s paper. Based on the results of the mercury intrusion tests, it is found t hat the micropore surface fractal dimension is 2.40 for the soil sample wit h the dry density of 1.50 g/cm(3), and is 2.47 for the soil sample with the dry density of 1.60 g/cm(3). By using the micropore surface fractal model, the shear strength formula for expansive soils is obtained. All the parame ters in the proposed shear strength formula are constant, and are independe nt of matric suction. The validation of the proposed shear strength formula is proven by the results of the triaxial compression tests on an expansive soil taken from Ningxia, China.