For better numerical analyses of grouting performance during tunneling, it is urgently required to effectively estimate the characteristics of grouted soils around tunnel.

This study suggests a method to characterize grouted soils around tunnel using elastic waves. 

All specimens are prepared by mixing Joomunjin standard sand with Portland cement at 170% water content, following in-situ conditions in grouting practice. 

Direct shear tests are performed at different curing times. And also elastic wave velocities are continuously measured using piezoelectric bender elements.

Experimental results show that shear strengths as well as elastic wave velocities increase with the curing time. 

Thus, shear strength or strength parameters (i.e., c and f) can be uniquely correlated to elastic wave velocities (i.e., Vp and Vs).

It is possible to characterize grouted soils around tunnel using elastic waves.