LAGRANGIAN ANALYSIS FOR A SET OF PARTICLE VELOCITY PROFILES MEASURED IN REMOLDING LOESS UNDER ONE-DIMENSIONAL STRAIN EXPERIMENT

Utilizing a single-stage light gas gun, plane shock-wave experiments were performed on the remold loess with a density of 1.8 g/cm³ and a saturation degree of 22%, in order to determine the dynamic behavior of the soil. The material of the projectile was PMMA. Wave motions were detected by four electromagnetic particle velocity sensors whose configuration were like П. The sensors were directly embedded into the remolding loess through the remolding process. The theoretical derivation and solution process of Lagrangian analysis based on one-dimensional strain was introduced in detail. The strain and stress profiles were determined through Lagrangian analysis of a set of particle velocity profiles measured in three typical experiments. The strain-stress relation with loading and unloading processes was obtained, which showed the hysteresis loop effect of the remolding loess. Based on this strain-stress relation, the particle velocity profiles were back analyzed. The difficulties encountered in the Lagrangian analysis were also discussed.