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SOIL REINFORCEMENT BY ROOTS

377

Citations

0

References

1981

Year

TLDR

The study extends a root‑soil model to predict how root stretching, slipping, and breaking of various sizes increase soil shear resistance. Root mechanical properties (Young’s modulus, tensile strength, diameter) of pine and barley were measured and combined with diameter distributions in the shear zone to feed the extended model. Model–experiment comparison revealed that the soil‑root bond strength (≈25 g cm⁻²) is the critical parameter limiting reinforcement, outweighing root strength.

Abstract

A root-soil model developed previously has been extended to predict the amount of increase in soil shear resistance (root reinforcement) produced by stretching, slipping, and breaking roots of various sizes. We measured Young's moduli, tensile strengths, and diameters of pine and barley roots, finding that both moduli and strengths decreased with increasing root diameter. These data and root diameter distributions in the shear zone of 0.25-meter diameter (pine) and 0.1-meter diameter (barley) soil columns were applied to the model. Comparison of model simulations with experiments showed that ø', the strength of the soil-root bond, is the most important unmeasured model parameter. Its value, rather than root strength, limited root reinforcement in saturated clay loam with both plant species and was of the order of 25 grams per square centimeter.