Laboratory large-scale pullout investigation of a new reinforcement of composite geosynthetic strip

Abstract

In this paper, more than 70 large-scale pullout tests were performed to evaluate the performance of an innovative composite geosynthetic strip (CGS) reinforcement in sandy backfill. The CGS reinforcement is composed of a geosynthetic strip (GS) and parts of a scrap truck tire as transverse members. The experimental pullout results for the CGS reinforcement were compared with the suggested theoretical equations and ordinary reinforcements, including the GS, the steel strip (SS), and the steel strip with rib (SSR). The pullout test results show that adding three transverse members to the GS reinforcement (CGS3) with S/H = 6.6 (where S and H are the space and height of the transverse members, respectively) increases pullout resistance by more than 120%, 170%, and 50% compared to the GS, the SS, and the SSR, respectively. This result shows that the CGS3 (CGS with three transverse members) reinforcement needs at least 55.5%, 63%, and 33.3% smaller length compared to the GS, the SS, and the SSR, respectively. In general, implementation of mechanically stabilized earth wall (MSEW) with the proposed strip may help geotechnical engineers prevent costly designs and solve the problem of MSEW implementation in cases where there are limitations of space.

Keywords

• Pullout resistance
• Composite geosynthetic strip (CGS)
• Soil–geosynthetic interface
• Scrap tires
• Large-scale pullout tests