New numerical scheme in the finite-element method for evaluating the root-reinforcement effect on soil slope stability

摘要

A new numerical scheme in the finite-element method was used to simulate both the progressive nature of failure and the interaction of the soil-root matrix continuum under dry and fully saturated conditions. Computations suggested that a certain range of root area ratio (the effective RAR range, or ERAR range) should be identified for a given slope geometry, vegetation type and maturity period. The ERAR range represents all the RARs that impart a factor of safety (FOS) greater than or equal to a particular FOS (the benchmark FOS). The benchmark BMFOS is the anticipated FOS, depending on factors such as demographic distribution and proximity to utilities. Beyond the ERAR range, vegetation does not impart stability to the slope. Theoretically, higher ranges of RAR beyond the ERAR range (the ineffective RAR range) can cause slope failure. This new numerical scheme evaluates the root-reinforcement effect on slope stability. This information is useful for analysing, designing and implementing soil-bioengineering slopes.