Dynamic triaxial tests are carried out to research the characteristics of fly ash soil improved by rubber particles such as the dynamic strength

dynamic modulus

cohesion and internal friction angle. Comparing with the normal fly ash soil

the experiment results demonstrate the conclusions as follows. Both of the dynamic strengths of the two soils are decreasing as the destruction cycles increasing under the same confining pressure. And the dynamic strengths of the two soils are increasing as the confining pressure increasing at the same destruction cycle. The cohesion is 203.73 kPa and the internal friction angle is 11° of the fly ash soil

at the same time the cohesion is 227.26 kPa and the internal friction angle is 17° of the improved soil. The cohesion increases 23.53 kPa

about 11.55%. The initial tangent modulus and the average dynamic modulus are higher than the data of the improved soil. The experimental result shows that the fly ash soil improved by rubber particles has high dynamic strength

cohesion and internal friction angle large. So that rubber particles of fly ash improved soil as subgrade freezing cold season blocking layer material.