Dynamic properties of saturated compacted soils

Dynamic properties of saturated compacted soils are very important parameters in analyzing seismic responses of compacted earth dams. Few test results were found in the past literatures. Saturating the compacted soil specimens is very difficult by using traditional saturation methods to satisfy the requirement of test standard. Thus, the complete test results for dynamic properties are difficult to find in the past. This paper proposed two vacuum-saturation methods for improving the saturation of the compacted soils. One is for compacted cohesionless soils. The other is for compacted fine-graded soils. Test results showed that both methods can make the Skempton's coefficient B greater than 0.95 for all specimens. The testing samples from the borrow areas of a planning earth dam included SM, ML and CL soils. Complete dynamic properties of all three soils were measured by resonant column test (RCT). The measured properties included the maximum shear modulus and normalized modulus and damping ratio curves which are much different from the typical curves of ordinary soils and the other dam materials. The empirical equations correlating the maximum shear modulus, void ratio and effective confining pressure were proposed for different compacted soils.