The dynamic properties of the ground while being compacted by the vibration oi vibratory roller were evaluated with the help of laboratory experiments. The results are as follows.
(1) Assuming the ground and roller system as a Voigt model, we need require K, M in eqs.(1) to get resonance frequencies f_n. We can get k_s by eqs.(7)-(12) substituting 1/ 10. of Young's modulus from a triaxial test for E, because of the relationship between elastic and plastic deformation from laboratory experiments.
(2) Measured resonance frequencies are 25-29 Hz for Cr., 27-32 Hz. for Rm. and 30-33 Hz. for Tr.(Fig. 3).
(3) Calculating results by the above procedures are rather smaller than experimental values except Tr. which almost coincide, but are much better than other equations.
(4) f_n of the ground is very much dependent on the density of field.
(5) The coefficient of damping is smaller than 0.1.
(6) From the above results we are able to get the dynamic properties of the ground by a vibratory roller and those results can be said to coincide with the values measured already by other procedures.
(7) Suppose that the compaction of soil depends only upon the magnitude of the force on the soil body, we had better compact according to the resonance frequency of the soil.