Root mass density (RMD) is introduced as the core parameter in the flexible friction-stiffened model of the root–soil complex to build the improved model so that the parameter values have better operability. First, "RMD/k" was used to replace the original model parameter "A/n," and the improved flexible friction stiffened model with RMD as the core was derived in the flexible state. Then, the root distribution test, single-root tensile test, and shear test of the root–soil composite were carried out to investigate the root distribution patter...
