Based on modern ideas of thermomechanics, small strain dynamic dissipation function of Hardin-Drnevich model for soils is formulated using the assumptions of the beeline and the skeleton curve shift laws. The first and the second threshold shear strain are proposed. Both the two threshold shear strains do depend significantly on the dynamic parameters for soils. Comparison between the results of eight kinds of cohesionless soils, it is shown that the two threshold shear strains decrease when the maximum dynamic shear modulus coefficient and exponent increase. The first threshold shear strain basically does not change with the change of internal friction angle. However, for the second threshold strain, a monotonically increasing function and monotonically decreasing function can be used to model the change with respect to the internal friction angle for the beeline and the skeleton shift stress respectively.