CYCLIC AND DAMPING PROPERTIES OF SILICATE-GROUTED SAND

Dynamic properties such as shear modulus, damping ratio, and fatigue strength of a sodium silicate-grouted sand were investigated using both destructive and nondestructive tests. Cyclic compression behavior of grouted sand was investigated in load control mode at a frequency of 1.0 Hz. The hysteretic behavior of grouted sand was studied with the number of loading cycles and curing times. The impact-echo test, a nondestructive method, was used to determine the dynamic properties of grouted sand cured up to 2 years. Variation of strength with the number of loading cycles (fatigue life) is quantified using a probabilistic approach. The compressive modulus of the grouted-sand system decreased with an increased number of cyclic loadings. The damping ratio for silicate-grouted sand increased from 3% at early stages of loading to 6% before failure. The dynamic moduli and damping ratio obtained from the impact-echo method were in agreement with those from cyclic compression tests.