Undrained Cyclic Shear of Saturated Sand.

摘要

Quantative data are presented and analyzed giving the effective confining pressure,shear modulus,damping and axial strain as a function of cycles of loading. Normalized empirical expressions based on initial conditions are developed to describe the measured parameters. The data was obtained from hollow cylinder simple shear tests of saturated Ottawa sand. Both quasi-static (1/10Hz) and resonance tests (30to 100Hz) were performed. Cyclic shear strain amplitudes to 0.15percent were maintained constant for the duration of each test. Dynamic pore pressures measured with a transducer mounted at the base of the speciman were less than 5percent of the confing pressure for the largest strain amplitudes in the test program. Dilation as measured by the axial vibration of the specimen was also very small. The basic approach used for these data should be applicable to other gradations,other cohesionless soils and to cases where confining pressure is not isotropic,but,the particular values within the empirical equations may be different. (Author)