Abstract:

Through repeated load-unloading triaxial shear tests, characteristics of deformation and damping of EPS beads-mixed lightweight soil under repeated load-unloading were studied. Laws between axial accumulative strain and axial total strain, between modulus of resilience and axial total strain, and between damping ratio and axial total strain were analyzed under different confining pressures, different cement-dry soil ratios and different types of soils. Results show that the axial accumulative strain and the axial total strain is a linear relationship. The modulus of resilience increases as the confining pressure and the cement-dry soil ratio increase. Under a range of the confining pressures and the cement-dry soil ratios, the modulus of resilience of sand type lightweight soil is larger than that of silty clay type lightweight soil when the axial total strain is smaller than 8%. While it changes to the opposite side when the axial total strain is larger than 8%. Curves between the modulus of resilience and the axial total strain can be fitted by diminishing power functions. The damping ratio of the EPS beads-mixed lightweight soil increases as the axial total strain increases, and decreases as the confining pressure and the cement-dry soil ratio increase. The damping ratio of the sand type lightweight soil is smaller than that of the silty clay type lightweight soil, but differences of the damping ratio between the two types of lightweight soil are small and the damping ratio is an approximate constant.

Key words: EPS beads-mixed lightweight soil, repeated load-unloading, axial accumulative strain, modulus of resilience, damping ratio