Aghaei Araei، A. نويسنده Department of Geotechnical Engineering, Building and Housing Research Center (BHRC), Tehran, P.O. Box 13145-1696, Iran , , Razeghi، H.R. نويسنده School of Civil Engineering, Iran University of Science and Technology (IUST), Narmak, Tehran, P.O. Box 16765-163, Iran , , Ghalandarzadeh، A. نويسنده , , Hashemi Tabatabaei ، S. نويسنده Department of Geotechnical Engineering, Building and Housing Research Center (BHRC), Tehran, P.O. Box 13145-1696, Iran ,
This paper studies loading rate effect on stressstrain behaviors of high compacted rockfill
materials. The large scale triaxial-dynamic equipment was used for this propose. To check the equipment
capabilities, tests have been carried out on elastic spring and damping rubber specimens. The laboratory
tests results indicate that the loading rate effect in elastic metal spring is negligible, while it has
considerable effects on stressstrain behaviors in damping rubber, and especially in rockfill materials.
The laboratory test results on rockfill materials have shown that dry specimens have higher E and D
values compared to the saturated samples. Anisotropic specimens have higher Youngʹs modulus and less
damping ratio in comparison to isotropic samples. Generally, the influence of the main parameters on E
and D in rockfill specimens is initial vertical effective stress and loading frequency, respectively. The high
compacted rockfill specimen exhibits a non-destructive response to the application of cyclic loading below
a threshold axial strain level of < 0.005%. Since the frequency effect was observed in the strain levels lower
than 0.005%, and there is not meaningful build up of pore pressure in this strain level, therefore any effect
of excess pore water pressure on the frequency effect is negligible.