Experimental study on strength characteristics of geogrid-reinforced loess

A series of consolidated undrained shear tests are carried out on geogrid-reinforced remolded loess samples, the effects of geogrid layers and reinforcement method on the strength characteristics of loess are investigated.The test results show that the loess strength increases under horizontal reinforcement layers, however, it decreases under inclined reinforcement condition.In case of horizontal reinforcement, the strength of the loess will increase as the reinforcement layers increase, moreover, there is an optimal reinforcement layer(reinforcement spacing), when the optimal layer is exceeded, the improvement effect is inconspicuous.The inclined reinforcement tests show that when the reinforcement angle is 0°, the loess sample shows the largest shear strength, however, the smallest strength is observed while the inclination angle of reinforcement reaches 45°+φ/2.The reinforcement effect will only play a role when the axial strain of the loess sample reaches about 3%~5%, indicating that a sufficient deformation condition is required to improve the strength of the soil, in this case, the reinforced material will show its stretchability to improve the shear strength of the soil.