PULL-OUT RESISTANCE OF POLYESTER STRAPS AT LOW OVERBURDEN STRESS

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