Written by: Bryan Wedin, Chief Engineer An accurate understanding of creep resistance is essential to proper material selection when using polymers, and in the case of geocells, this science is being misapplied. The definition of creep deformation is “the tendency of a solid material to move slowly or deform permanently under the influence of mechanical stress.” This potential failure mode creates fear and uncertainty among designers wherever the possibility of creep factors exists. Yes, creep can occur in almost all materials including plastics, metals, and concrete. In cases such as bridge and building design, it is important to properly understand creep factors and account for creep in engineering calculations. However, in the case of designing with geocells for load support, creep factors have no relevance. What causes creep? In order for creep to occur, two factors must be present: 1) A constant load applied to the area and 2) A sustained deformation of the geocells. Creep only applies when there is a sustained load on a material for an extended period. In a case of repeated on- and off-loading, this type of deformation would be governed by fatigue, not by creep, because it is not a constant applied load. The… Read more »