Abstract:
To provide the basis for calculating the slope stability and selecting the type of herbs, the relationship between the increment of unconfined compressive strength of root−soil and the root distribution characteristics were investigated. The additional cohesion (Δ
c) of root−soil of three herbs, which were planted in the PVC tubes, was measured by the unconfined compressive test. The values of root distribution characteristics were estimated by 2013WinRHIZO. The results showed that: ① At depth of 0~25, the Δ
c of
Setaria anceps Stapf ex Massey L.,
Dactylisglomerata L. and
Medicago sativa L. was 4.75, 4.00 kPa and 1.11 kPa, respectively. At depth of 25~50 cm, the Δ
c was 3.20, 2.33 kPa and 0.83 kPa, respectively; ② The values of root distribution characteristics of
Medicago sativa L, including root length density (
ρLen), root surface area density (
ρSA) and average diameter (
Da), were significantly different with that of
Setaria anceps Stapf ex Massey L. and
Dactylisglomerata L. ; ③ The Δ
c of
Setaria anceps Stapf ex Massey L. and
Dactylisglomerata L. had significant or extremely significant correlation with Q,
ρLen,
ρSA,
ρRV and
Da. The Δ
c of
Medicago sativa L. had a significant quadratic correlation with
ρLen and
ρSA, and its Δ
c had no correlation with
ρRV, Q and
Da. The conclusions are as follow: The Δ
c of root−soil had significant correlation with
ρLen and
ρSA. The
ρLen and
ρSA could be used to predict the soil reinforcement capacity of root system. Moreover, the soil reinforcement capacity of
Setaria anceps Stapf ex Massey L was the best.