Pull-Out Resistance of Polyester Straps at Low Overburden Stress

Abstract

The pull-out resistance of a high tenacity polyester strap at a low overburden stress of less than 100 kPa was studied with a large-scale pull-out box. Three different types of soil hauled from active construction sites were used. The test results indicated that the friction factor, as defined by the ratio of the average failure shear stress to average normal stress, increased with a reduction in the overburden stress. This increase was observed to be more significant for the soil with a high dilatancy. The difference in the friction factor between the Grade 20 and 30 straps was slight. These observations can be consistently explained by the constrained dilatancy hypothesis.