Centrifuge modelling of root reinforcement of slopes

The stability of slopes may be modified by plant roots that permeate the soil. Thus, vegetation may form a natural method of mechanically reinforcing soil and preventing shallow slope failures. To date, the effect of vegetation is not considered routinely in design largely because of uncertainty in application of existing vegetation reinforcement models. This paper reports a series of centrifuge model tests conducted to investigate the mechanical stabilisation of slopes by plant roots. Compacted clay embankments were constructed with steep (45°) side slopes and brought to failure by increasing the height of the internal water table. By comparing the collapse behaviour of fallow (i.e. unreinforced) slopes to that of those reinforced by root analogues or real willow roots, the reinforcing effect can be found