THE MODEL EXPERIMENT TEST AND DISCRETE ELEMENT SIMULATION OF CONE PENETRATION TSET IN CEMENTED SAND

Artificial cemented sands were prepared by adding cement into the sand,and the effect of cementation between sand particles on cone penetration test results was investigated by self-developed model experiment equipment of cone penetration test. The test results show that the cone resistance q_c increased with the increase of cement content. The increase in q_c value was mainly caused by the increase of cohesion of cemented sand. When estimating the mechanical parameters of cemented sand according to the q_c value,if the influence of structure is not considered,the internal friction angle of cemented sand will be overestimated. The ratio of initial shear modulus to cone resistance G_max/q_c increased with the increase of cement content,so the structural strength of sand can be qualitatively evaluated according to the value of G_max/q_c. The influence mechanism of bond strength among particles on q_c was analyzed by discrete element simulation. The simulation results show that the penetration caused the breakage of bonds among particles near the probe rod. The greater the bond strength among particles was,the greater the force required for particles to arise movement,the greater the contact force of particles around the cone tip,therefore,the q_c value increased with the increase of bond strength. The research results can provide theoretical guidance for the analysis and application of cone penetration test data in cemented sand.