Investigating shear stability of rugby union natural turf pitches

The stability of natural Rugby Union pitches continues to be a recurring problem at all levels of the game. The effects of poor turf stability are seen when the pitch surface shears under player loading, creating divots and an uneven surface. However, perhaps surprisingly, there is no objective quantitative mechanical test method for assessing the stability of the natural turf, with regard to shear resistance. This paper details initial work undertaken to assess the effectiveness of current shear testing apparatus in predicting stability for Rugby Union. It has been suggested there are two failure areas in pitch constructions: One on the surface and one deeper in the soil. The results show variability in natural turf constructions, and that current shear test methods are less effective in sandy soils. Penetration readings were relatable to hardness, however shear stability testing requires development.