Effect of the Slit on the Mechanical Tearing Behavior of High-Density Polyethylene and Polyester Geocell Strips

Abstract

Geocells are widely applied in numerous infrastructure constructions, like heavy-haul railways and ports. The mechanical tearing behavior of a geocell strip is crucial to the stability of the geocell-reinforced soil structures. At present, extensive studies have been conducted on the tensile characteristics of geocell strips, while limited research has been performed to investigate the post-damage mechanical tearing behavior of geocell strips. Meanwhile, there is also a lack of research on the comparison of performance of strips before and after damage. In this paper, a series of trapezoidal tearing tests were performed on high-density polyethylene (HDPE) and polyester (PET) geocell strips. The tearing test results and failure mode of trapezoidal specimens with a slit were investigated, and the effect of the slit on the strength and deformation characteristics of the specimen were discussed by introducing the “damage ratio of tearing force (RTF)” and “damage ratio of tearing displacement (RTD)”. In addition, the mechanical tearing behavior of HDPE and PET trapezoidal specimens was also compared. The test results indicated that the failure mode of HDPE and PET specimens subjected to tearing force was ductile and brittle failure. The strength and deformation characteristics of post-damage HDPE and PET trapezoidal specimens decreased. The slit had a significant impact on the tearing displacement of HDPE and PET specimens, especially the post-peak tearing displacement. The post-peak tearing displacement of HDPE was 10.99 times that of PET. The peak tearing force of the HDPE specimen without the slit was about 1.61 times that of specimen with the slit. Before local tearing, the peak tearing force of the PET specimen without the slit was about 3.27 times that of the specimen with the slit. The strength damage to the HDPE and PET geocell strips caused by the slit was 38.0%, and 69.46%. The impact of the slit on the tearing force of the PET specimen was greater than that of the HDPE, and was 1.82 times for the HDPE. This study can enhance our understanding of the mechanical tearing behavior of the geocell strip after damage and develop effective mitigation measures.