Study on Constitutive Model for Root System of Korshinsk peashrub in Axial Tension

Abstract

Constitutive model for root system of Korshinsk peashrub (Caragana korshinskii Kom.) in axial tension is an important tool for analyzing the mechanism of soil reinforcement of root system. This model enables a mechanical analysis on strength and deformation of root system and root-soil complex. We carried out axial tension test of root system of Korshinsk peashrub in this paper and discussed the stress-strain relation. Based on the experimental results, the constitutive model for root system of Korshinsk peashrub in axial tension was established. Results showed that: (1) When the strain was smaller than 4%, the stress-strain relation was linear for single root, corresponding to linear elastic deformation; when the strain was larger than 4%, the single root underwent plastic deformation; (2) Elastic modulus of the root system was related to root diameter by a power function. The smaller the root diameter, the higher the elastic modulus was; (3) Root diameter was related to the ultimate tensile strength of root also by a power function. The smaller the root diameter, the higher the ultimate tensile strength of root was; (4) The tensile stress-strain curve of the root system divided into ascending segment and descending segment, which was fitted by parabola and curvilinear model, respectively.

Keywords

• Root system
• Tensile test
• Stress-strain curve
• Constitutive model