A study on dynamic parameters and seismic response of interbedded soil

By using resonant column apparatus, the dynamic parameters of interbedded soil and other soils in two sites are tested; the curves of dynamic shear modulus ratio G/G(max) and damping ratio versus dynamic shear strain amplitude gamma of the soils in two sites are given. Compared with the variation range of G/G(max) vs gamma and D vs gamma curves of other soils, it is obviously that the G/Gmax vs.. and D vs gamma curves of mucky silty clay and fine sand interbedded strata are more close to those of soft clay. By calculating the seismic response of the two sites, the results show that the interbedded soil weakens the peak acceleration greatly and its maximal shear strain amplitude is very big which is near to be failure under horizontal earthquake. The dynamic characteristic of interbedded soil is similar to that of soft soil; and this property is caused by its special conformation, i.e. the feeble horizontal joint planes are overgrown.