Pullout Characteristics of Geosynthetics Reinforced Earth Using Multilayer Spreading Pullout Test

Abstract

Pullout test equipment for examining pullout characteristics in a reinforced earth structure is relatively larger than direct shear testing machines and requires much time and expenses in preparing samples. Moreover, because of irregular stress distributions with respect to the length of reinforcements, it is difficult to analyze pullout test results. In this study, we developed a multilayer spreading pullout apparatus enabling the pullout test in the order of a top stage, middle stage, and bottom stage with different loads once a ground model is prepared, suggesting an efficient method of a multilayer spreading pullout test. The pullout test is carried out at least three times with the prepared ground model while changing confining loads. Jumunjin sand was used to verify the developed pullout test apparatus and to analyze pullout characteristics of each reinforcement. The analysis reveals that the difference between angles of pullout friction is approximately 0.86 to 1.3 ∘ which is distributed within the error range of a pullout test. As a result, the multilayer spreading pullout apparatus is applicable as a new pullout apparatus, and the suggested method of multilayer spreading pullout test is identified as a pullout test technique efficiently to obtain pullout parameters.

Interface Frictional Properties of Geogrid-Reinforced Pond Ash

“…From the test results, it can be observed that pullout resistance forces have increased with an increase in normal stresses from 37 to 110 kPa, and all the maximum pullout forces were achieved within the deformation range of 50 to 80 mm. Beyond this, the pullout resistance forces were observed to be decreased because of particles rearrangement among themselves and followed by reinforcement pullout [17]. The improvement in pullout resistance against normal load is due to the development of passive resistance of transverse reinforcement.…”

Mechanical Response of a Novel “Anti-slide Pile + Support Column” Composite Retaining Structure

“…Therefore, taking targeted control measures combined with geological conditions is the basis and premise of achieving favorable governance effects. At present, the traditional slope stability control technology, such as unloading, antislide pile, anchor-plate retaining, and reinforced soil [14][15][16][17][18], can hardly achieve the desired control effect in slope engineering with the abovementioned geological conditions given the limitations in their technical features.…”