# Experimental Study of Influence of Plant Roots on Dynamic Characteristics of Clay
## 3 Experimental Results Analysis
### Influence of Plant Root Systems on Soil Damping Ratio
#### 3.2.2 Different Root Mass Density  
The maximum damping ratio and the damping ratio-shear strain curves for soils with different root mass densities are illustrated in Figures 13 and 14. It is evident from these figures that under a confining pressure of 100 kPa, the maximum damping ratio (\(\lambda_{max}\)) was 5.36% when the root mass density was 0. As the root mass density increased to 1.5% \(\mathrm{g\cdot cm^{-3}}\), the damping ratio decreased to 4.92%, reaching the minimum critical value. Further increasing the root mass density caused the damping ratio to rise, reaching 5.39% at a root mass density of 3% \(\mathrm{g\cdot cm^{-3}}\). Under confining pressures of 200 kPa and 300 kPa, the relationship between the damping ratio and root mass density followed the same trend as under 100 kPa, showing an initial decrease followed by an increase. Specifically, the damping ratio decreased from \(\lambda_{max}\)= 4.76% at \(\rho_{g}\) = 0 and \(\lambda_{max}\) = 4.46 at \(\rho_{g}\) = 0 to the minimum critical values of \(\lambda_{max}\) = 4.44% at \(\rho_{g}\) = 2% \(\mathrm{g\cdot cm^{-3}}\) and \(\lambda_{max}\) = 4.18% at \(\rho_{g}\) = 2.5% \(\mathrm{g\cdot cm^{-3}}\). When the root mass density reached 3% \(\mathrm{g\cdot cm^{-3}}\), the maximum damping ratio increased to 4.8% and 4.27%, respectively. Notably, under 100 kPa and 200 kPa confining pressures, the maximum damping ratio of samples with a 3% \(\mathrm{g\cdot cm^{-3}}\) root mass density consistently surpasses that of samples with 0% root mass density. This can be attributed to the fact that the inclusion of roots in the samples enhances the soil's ductility, facilitating energy dissipation and resulting in an elevated damping ratio. Simultaneously,  
Figure 11: The maximum damping ratio of soil with different root distribution patterns.  
Figure 12: \(\lambda\) - \(\gamma\) relationship curves for soil with different root distribution patterns.  
it leads to a denser soil structure, increasing the contact area between soil particles and between soil particles and roots. However, this is not conducive to energy dissipation and results in a lower damping ratio. Simultaneously, it leads to a denser soil structure, increasing the contact area between soil particles and between soil particles and roots. However, this is not conducive to energy dissipation and results in a lower damping ratio. Beyond this point, roots predominantly enhance the soil's ductility, leading to an increased damping ratio. In summary, the damping ratio initially decreases and then increases with an increase in root mass density. In practical slope scenarios, the growth of plant roots tends to loosen the surface soil, reducing the compactness of the soil on the slope's surface. [PERSON] et al. [39] previously concluded that during the growth process of roots, large pores may form through the soil, but these pores are local and beneficial. While roots enhance the soil's ductility, their effect on reducing soil compaction is favorable for energy dissipation.