Large-scale Cyclic Simple Shear Experimental Study On Dynamic Characteristics Of Geocell Reinforcing Rubber Sand Cushion

The research group developed a large-scale cyclic simple shear instrument, the specimen diameter is 700 mm, height is 200~500mm(adjustable), the maximum shear displacement is 100 mm. The instrument is used for geocell reinforcing rubber-sand mixture and rubber-sand mixture composite cushion cyclic simple shear test, considering five kinds of rubber content(0%,10%,20%,30%,50%) and four consolidation pressure(50k Pa,100 k Pa,200 k Pa,300 k Pa).Make comparison and analysis both the large-scale test results and existing research about rubber-sand dynamic characteristics.The results indicate:1. Under dynamic cyclic loading, reinforced and non-reinforced rubber-sand show hysteretic characteristics. With the shear strain increases, the hysteresis curve gradually plump, the slope lower. Non-reinforced rubber sand hysteresis curves obvious anti-S-type in the large strain,the reinforcing rubber-sand is not clear.2. Reinforced and non-reinforced rubber-sand dynamic shear modulus decrease with shear strain amplitude increase, reduce with the rubber content increase, increase with consolidation pressure increase. Geocell make the rubber-sand mixture dynamic shear modulus a slight increase.3. Reinforced and non-reinforced rubber-sand damping ratio increase with shear strain amplitude increase, decrease with consolidation pressure increase. The rubber-sand damping ratio increases significantly with rubber content increases in the small strain, but not obvious in the big strain.4. In this paper, large cyclic simple shear test dynamic characteristics of the resulting rubber sand test results and routine laboratory test results have good consistency. Combined results in the small strain, shows the rubber-sand dynamic shear and damping ratio learning curve on a full range of strain.