Experimental study on dynamic mechanical properties of compacted clay under impact compressive loading

In order to investigate compressive mechanical properties with strain rates on compacted clays,the specimens were subjected to axial impact with different projectile speeds by using the split Hopkinson pressure bar made by polycarbonate.Experimental results show that the parameters related to peak stress and strain are dependent on the strain rate,and the effects of the strain rate can be expressed by exponential approximations,namely peak stress,dynamic strength increase factor,specific energy absorption and overstress,however the parameters related to strain,namely strain and peak strain increase factor,can be expressed by linear approximations.At the same time,further analysis of the relationship between overstress and strain rate(including the quasi-static) show that when the strain rate is lower than the reference strain rate,the dependence of the dynamic strength on the strain rate is relatively small,and when higher than the reference strain rate,the dynamic strength is significantly influenced by the strain rate.