Evaluation of deformation modulus of cemented sand using CPT and DMT

A series of penetration tests (CPTs and DMTs) and 1-dimensional compression tests are performed on artificially cemented sands to investigate the cementation effect on the deformation characteristics of sand. The constrained modulus (M) is observed to be more sensitive to the cementation than the measurements by CPT and DMT because the cementation effect is not fully reflected in the CPT and DMT results due to the damage of cementation induced during the penetration. As the cementation causes similar effects on the horizontal stress index (K_D) and cone resistance (q_c), the K_D-q_c/sigma;_v' relation is observed to be similar for both uncemented and cemented sands, regardless of the cementation degree. It is also shown that the dilatometer modulus (E_D) of cemented sand is larger than that of uncemented sand at the same q_c and the difference increases with the cementation degree. The M/q_c and M/E_D of cemented sand are significantly larger than those of uncemented sand. The M/q_c and M/E_D of cemented sand decrease with increasing q_c, while those of uncemented sand are almost constant. It is also found that the M/E_D-q_c/p_a relationship of cemented sand is independent of the cementation degree.