A study of multilayer soil-fly ash layered system under cyclic loading

In the present investigation, the cyclic load deformation behaviour of soil-fly ash layered system isstudied using different intensities offailure load (i =25%, 50% and 75%) with varying numher ofcycles (n =10, 50 and 100). an attempt has heen made to establish the use offly ash as afill material for embankments ofhighways and railways and to examine the effect of cyclic loading on the layered samples ofsoil and fly ash.the number of cycles, confining pressures and the intensity of loads at which loading unloading has beenperformed were varied. the resilient modulus, permanent strain and cyclic strength factor are evaluated fromthe test results and compared to show their variation with varying stress levels. the nature of stress-strainrelationship is initially linear for low stress levels and then turns non-linear for high stress levels. the testresults reveal two types of failure mechanisms that demonstrate the dependency of consolidated undrainedshear strength tests of soil-fly ash matrix on the interface characteristics of the layered soils under cyclicloading conditions. data trends indicate greater stability of layered samples of soil-fly ash matrix in terms offailure load (i) at higher number of loading-unloading cycles, performed at lower intensity ofdeviatoric stress,and (ii) at lower number of cycles but at higher intensity of deviatoric stress.