A series of parallel tests are carried out on the rockfills of Mashan pumped storage power station in the city of Wuxi. It is found that the results of large scale triaxial compression tests

confined-uniaxial compression tests and seepage tests for twice on three kinds of rockfills are very closer. The stress-strain relationships of three rockfills are consistent with the Duncan-Chang hyperbolic model

and the volume dilates under lower confined pressures. The low compressibility of rockfills is due to their stiffness. The bounce is very little when unloading

so it is thought that the compression deformation is basically plastic. Additionally

the permeabilities for three rockfills accord with Darcy Law. Therefore

the test results show that the rockfill materials satisfy the design requests of engineering

and also validate that the stable properties of rockfills

the feasibility of experiment methods and the accuracy of apparatuses are all accepted.